KR20130018938A - Metal complex dye, photoelectric conversion element and dye-sensitized solar cell - Google Patents

Abstract

[식 중, R¹ 및 R² 는 특정의 치환기를 나타내고; L¹ 및 L² 는 에테닐렌기, 에티닐렌기 및 아릴렌기로 이루어진 군으로부터 선택되는 적어도 1 종의 기로 이루어진 기를 나타내고, R¹ 또는 R² 및 바이피리딘과 공액하고 있고; 에테닐렌기 및 아릴렌기는 치환 또는 치환되어 있지 않을 수 있고; R³ 및 R⁴ 는 치환기를 나타내고; n1 및 n2 는 0 내지 3 의 정수를 나타내고; A¹ 및 A² 는 산성기 또는 그 염을 나타내고; n3 및 n4 는 0 내지 3 의 정수를 나타낸다].Metal complex dye containing ligand LL1 of the structure represented by following formula (I):

[Wherein, R ¹ and R ² represent a specific substituent; L ¹ and L ² represent a group consisting of at least one group selected from the group consisting of an ethenylene group, an ethynylene group and an arylene group, and are conjugated with R ¹ or R ² and bipyridine; The ethenylene group and the arylene group may be substituted or unsubstituted; R ³ and R ⁴ represent a substituent; n1 and n2 represent integers of 0 to 3; A ¹ and A ² represent an acid group or a salt thereof; n3 and n4 represent the integer of 0-3.

Description

Metal complex dyes, photoelectric conversion elements and dye-sensitized solar cells {METAL COMPLEX DYE, PHOTOELECTRIC CONVERSION ELEMENT AND DYE-SENSITIZED SOLAR CELL}

The present invention relates to a metal complex dye having excellent durability and photoelectric conversion characteristics, a photoelectric conversion element containing semiconductor fine particles produced by using the same as a sensitizing dye, and a dye-sensitized solar cell using such a photoelectric conversion element.

As solar cells used in solar power generation, solar cells made of a compound such as monocrystalline silicon, polycrystalline silicon, amorphous silicon, or a compound such as cadmium telluride or indium copper selenide have been the subject of major research and development, and some of them have been put into practical use. . However, in order to spread these solar cells widely for applications such as household power sources, these solar cells have problems such as low cost manufacturing, difficulty in securing raw materials, and long energy payback time. There is a need to overcome these problems. On the other hand, many solar cells manufactured using organic materials have been proposed for the purpose of providing a battery at a large area of the light condensing portion and at a low cost. However, in the solar cells which have been applied so far, the conversion efficiency is generally low and the durability is often poor.

Under such circumstances, a wet photoelectric conversion element and a solar cell using a titanium dioxide porous thin film spectroscopically sensitized by a ruthenium complex dye as a working electrode, and materials and manufacturing techniques for producing the same have been proposed (for example, , Patent Documents 1 and 2, and Non-Patent Document 1). A first advantage of the wet photoelectric conversion elements described in these documents is that inexpensive oxide semiconductors such as titanium dioxide can be used without high purity purification, so that photoelectric conversion elements can be provided at low cost. The second advantage of these wet photoelectric conversion elements is that since the dye used can absorb light in a wide range of wavelengths, it can absorb light in almost all wavelength ranges of visible light and convert it into electricity.

Until now, N719, Z907, J2, etc. are developed as a metal complex dye used for a photoelectric conversion element. The photoelectric conversion element manufactured using N719 initially shows high photoelectric conversion efficiency. However, the fall of conversion efficiency after use is large, and there exists a problem in durability of a battery. On the other hand, the photoelectric conversion element manufactured using Z907 has little fall of conversion efficiency after use. However, Z907 has a low initial value itself of photoelectric conversion efficiency compared with N719.

Moreover, the photoelectric conversion element containing the semiconductor fine particle sensitized with the metal complex dye which has a specific structure is proposed (for example, refer patent document 3). However, in terms of durability, the photoelectric conversion element described in Patent Document 3 is not sufficient. Moreover, J2 was developed as a pigment | dye with high initial stage conversion efficiency (patent document 4). However, the photoelectric conversion element is not sufficient even if it has the initial conversion efficiency and durability of J2.

Therefore, a photoelectric conversion characteristic such as conversion efficiency, and a dye excellent in durability after a long period of use, and excellent in durability, a photoelectric conversion element produced by using this as a sensitizing dye, and a dye sensitized embodiment composed of such a photoelectric conversion element Battery needed.

U.S. Patent 4927721 WO 94/04497 JP-A-2001-291534 ("JP-A" means unexamined Japanese patent application) Japanese Patent No. 4576494

 Nature, vol. 353, p. 737-740 (1991)

The subject of this invention is a metal complex pigment | dye which is excellent in durability, since the photoelectric conversion characteristics, such as conversion efficiency, and the fall of a photoelectric conversion characteristic are small even after using for a long time; Photoelectric conversion element manufactured using this as a sensitizing dye; And a dye-sensitized solar cell made of such a photoelectric conversion element.

The present inventors earnestly examined. As a result, a metal complex dye having a specific bipyridine ligand containing a specific substituent is excellent in durability and photoelectric conversion properties, and is produced using a photoelectric conversion element containing semiconductor fine particles produced using this as a sensitizing dye. One dye-sensitized solar cell was found to satisfy excellent conversion efficiency and durability. The present invention has been accomplished based on this point of view.

The problem of the present invention can be solved by the following means.

Metal complex dye containing ligand LL1 which has a structure represented by <1> following formula (I):

[Wherein,

R ¹ and R ² each independently represent a group represented by any one of the following formulas (II) to (VIII);

L ¹ and L ² each independently represent a group consisting of at least one group selected from the group consisting of an ethenylene group, an ethynylene group and an arylene group, and are conjugated with R ¹ or R ² and bipyridine; The ethenylene group and the arylene group may be substituted or unsubstituted;

R ³ and R ⁴ each independently represent a substituent; n1 and n2 each independently represent an integer of 0 to 3; when n1 is an integer of 1 or more, R ³ may combine with L ¹ to form a ring; when n2 is an integer of 1 or more, R ⁴ may combine with L ² to form a ring; when n1 is an integer of 2 or more, R ³ may be the same as or different from each other, or R ³ may combine with each other to form a ring; when n2 is an integer of 2 or more, R ⁴ may be the same or different from each other, or R ⁴ may combine with each other to form a ring; when n1 and n2 are each an integer of 1 or more, R ³ and R ⁴ may combine with each other to form a ring;

A ¹ and A ² each independently represent an acid group or a salt thereof; n3 and n4 each independently represent an integer of 0 to 3;

(Wherein,

R ⁵ , R ⁸ , R ¹³ , R ¹⁶ and R ¹⁹ each independently represent an alkynyl group or an aryl group which may each have a substituent;

R ⁶ , R ⁹ to R ¹² , R ¹⁴ , R ¹⁵ , R ¹⁷ , R ¹⁸ , R ²⁰ to R ²³ , R ²⁵ , R ²⁶ and R ²⁸ to R ³¹ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, An alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an amino group, a heterocyclic group, or a halogen atom; At least one of R ²⁵ and R ²⁶ represents an alkyl group;

R ⁷ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or a halogen atom;

Any of R ⁶ and R ⁷ , R ⁹ to R ¹² , any of R ¹⁴ and R ¹⁵ , R ¹⁷ and R ¹⁸ , R ²⁰ to R ²³ , any of R ²⁵ and R ²⁶ , and R ²⁸ to R ³¹ May combine with each other to form a ring;

Two R ²⁴ and two R ²⁷ present in the same group may be the same or different from each other, and each represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, but a plurality of R ²⁴ or a plurality of R ²⁷ Do not combine with each other to form a ring;

m1 to m6 each independently represent an integer of 1 to 5;

Y represents S, O, Se, Te or NR ³² ; X represents S, Se, Te or NR ³² ; R ³² represents a hydrogen atom, an alkyl group, an alkenyl group, an alkenyl group, an aryl group, or a heterocyclic group).

<2> in the above formula (I) of L ¹ and L ² are each independently a substituted or unsubstituted ethenyl group and / or represents an ethynylene to, conjugated with R ¹ or R ² and bipyridine, the <1> The metal complex pigment | dye of description.

Metal complex dye as described in said <1> or <2> represented by <3> following formula (IX):

M (LL1) (LL2) ( Z) p · CI formula (IX)

[Wherein M represents a metal atom; LL1 has the same meaning as LL1 in formula (I); LL2 represents a ligand represented by the following formula (X); Z represents a monodentate or bidentate ligand; p represents an integer of 0 to 2;

CI represents the counter ion when counter ions are needed to neutralize the charge in formula (IX);

(Wherein,

R ³³ and R ³⁴ each independently represent a substituent; n5 and n6 each independently represent an integer of 0 to 3; when n5 is an integer of 2 or more, R ³⁴ may be the same as or different from each other, or R ³⁴ may combine with each other to form a ring; when n6 is an integer of 2 or more, R ³³ may be the same as or different from each other, or R ³³ may be bonded to each other to form a ring; when n5 and n6 are each an integer of 1 or more, R ³³ and R ³⁴ may combine with each other to form a ring;

A ³ and A ⁴ each independently represent an acidic group; n7 and n8 each independently represent an integer of 1 to 4).

The metal complex dye as described in said <3> whose metal element M of <4> Formula (IX) is Ru, Re, Rh, Pt, Fe, Os, Cu, Ir, Pd, W or Co.

Metal complex dye as described in said <3> whose metal element M of <5> above-mentioned Formula (IX) is Ru.

<6> The metal complex dye according to any one of <1> to <5>, wherein Y in Formulas (II) to (VIII) is S.

<7> The metal complex dye according to any one of <3> to <6>, wherein the ligand LL2 is a ligand represented by the following Formula (XI):

[Wherein,

A ⁵ and A ⁶ each independently represent an acid group; R ³⁵ and R ³⁶ each independently represent a substituent; n9 and n10 each independently represent an integer of 0 to 3; when n9 is an integer of 2 or more, R ³⁵ may be the same as or different from each other, or R ³⁵ may be bonded to each other to form a ring; when n10 is an integer of 2 or more, R ³⁶ may be the same as or different from each other, or R ³⁶ may combine with each other to form a ring; when n9 and n10 are each an integer of 1 or more, R ³⁵ and R ³⁶ may combine with each other to form a ring].

<8> The metal complex dye according to any one of <3> to <6>, wherein the ligand LL2 is a ligand represented by the following Formula (XII):

[Wherein, A ⁷ and A ⁸ each independently represent a carboxyl group or a salt thereof].

<9> The metal complex according to any one of <1> to <8>, wherein R ¹ and R ² of the ligand LL1 are groups represented by any of formulas (II), (VII), and (VIII), respectively. Pigment.

<10> The metal complex dye according to any one of <1> to <9>, wherein L ¹ and L ² of the ligand LL1 are each an unsubstituted ethenylene group.

The metal complex dye in any one of said <3>-<10> with which the metal complex dye represented by <11> above-mentioned Formula (IX) is represented by any of following formula (XIII)-(XV):

[Wherein,

A ⁹ , A ¹⁰ , A ¹¹ , A ¹² , A ¹³ and A ¹⁴ each independently represent a carboxyl group or a salt thereof; R ²⁰⁰ and R ²⁰³ each have the same meaning as R ^{5 in} formula (II); R ²⁰² , R ²⁰⁵ , R ²⁰⁷ , R ²⁰⁸ , R ²¹⁰ , R ²¹¹ , R ²¹³ to R ²¹⁶ and R ²¹⁸ to R ²²¹ each have the same meaning as R ^{6 in} formula (II); At least one of R ²⁰⁷ and R ²⁰⁸ is an alkyl group; At least one of R ²¹⁰ and R ²¹¹ is an alkyl group;

R ²⁰¹ and R ²⁰⁴ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or a halogen atom;

R ²⁰¹ and R ²⁰² , R ²⁰⁴ and R ²⁰⁵ , R ²⁰⁷ and R ²⁰⁸ , R ²¹⁰ and R ²¹¹ , any of R ²¹³ to R ²¹⁶ , and any of R ²¹⁸ to R ²²¹ may combine with each other to form a ring. There is;

R ²⁰⁶ and R ²⁰⁹ each have the same meaning as R ^{24 in} formula (VII); R ²¹² and R ²¹⁷ each have the same meaning as R ^{27 in} formula (VIII);

m7 to m10 each independently represent an integer of 1 to 5;

Z represents a single or bidentate ligand; q1 to q3 each independently represent an integer of 1 to 2].

The metal complex dye as described in said <11> whose metal complex dye represented by <12> Formula (IX) is represented by Formula (XIII) or Formula (XV).

The metal complex dye as described in said <11> whose metal complex dye represented by <13> Formula (IX) is represented by Formula (XIII).

<14> The metal complex dye according to any one of <3> to <13>, wherein Z is isothiocyanate, isocyanate or isocelenocyanate.

<15> The photoelectric conversion element containing the semiconductor fine particle sensitized with the metal complex dye in any one of said <1>-<14>.

The photoelectric conversion element containing the semiconductor fine particle sensitized with the <16> some pigment | dye, and at least one of them is a metal complex dye in any one of said <1>-<14>.

At least one of the plurality of dyes has a maximum absorption wavelength at a longest wave side of 600 nm or more in a THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution. The photoelectric conversion element described.

<18> conductive supports; And

A semiconductor layer disposed to cover the conductive surface of the conductive support;

The photoelectric conversion element in which the metal complex dye in any one of said <1>-<14>, and the coadsorption agent which has one carboxyl group or its salt are supported on the surface of the semiconductor particle of the said semiconductor layer.

The photoelectric conversion element as described in said <18> whose <19> above-mentioned coadsorption agent is represented by following formula (XVI):

[Wherein Ra represents an alkyl group having only one acidic group or a salt thereof; Rb represents a substituent; n represents an integer of 0 or more; when n is an integer of 2 or more, a plurality of Rb may be the same or different from each other].

<20> The dye-sensitized solar cell containing the photoelectric conversion element in any one of said <15>-<19>.

According to the present invention, a metal complex dye having excellent durability due to less photoelectric conversion characteristics such as conversion efficiency and a decrease in photoelectric conversion characteristics even after long-term use; Photoelectric conversion element manufactured using this as a sensitizing dye; And the dye-sensitized solar cell which consists of such a photoelectric conversion element can be obtained.

Other additional features and advantages of the present invention will become more fully apparent from the following description with appropriate reference to the accompanying drawings.

1 is a cross-sectional view schematically showing an exemplary embodiment of a photoelectric conversion element according to the present invention.

The present inventors earnestly examined. As a result, the metal complex dye (hereinafter simply referred to as a dye) having a specific bipyridine ligand containing a specific substituent is excellent in durability and photoelectric conversion properties, and contains semiconductor fine particles prepared by using it as a sensitizing dye. It was found that the dye-sensitized solar cell manufactured using the photoelectric conversion element described above satisfies the excellent conversion efficiency and durability. The present invention is accomplished based on this point of view.

As shown in FIG. 1, the photoelectric conversion element 10 includes a conductive support 1; And a photoconductor layer 2 (also referred to as a "semiconductor film" or a "semiconductor layer"), a charge carrier layer 3, and a counter electrode 4, which are arranged in this order on the conductive support 1. . The conductive support 1 and the photosensitive member layer 2 constitute a light receiving electrode 5. The photosensitive member layer 2 has a semiconductor fine particle 22 and a sensitizing dye (hereinafter, also simply referred to as "color") 21. At least a part of the sensitizing dye 21 is adsorbed to the semiconductor fine particles 22 (the sensitizing dye 21 is in an adsorption equilibrium state, and a part thereof may be present in the charge carrier layer 3). The charge carrier layer 3 can function as a hole transport layer for transporting holes (holes), for example. The electroconductive support 1 in which the photosensitive member layer 2 is formed functions as a working electrode in the photoelectric conversion element 10. This photoelectric conversion element 10 can be worked in an external circuit 6 and can be operated as a photoelectrochemical cell 100.

The light receiving electrode 5 includes a conductive support 1; And the photoconductor layer 2 containing the semiconductor fine particles 22 on which the sensitizing dye 21 is adsorbed, which is applied on the conductive support 1. Light incident on the photoconductor layer 2 excites the dye. The excited dye has electrons with high energy, and these electrons move from the sensitizing dye 21 to the conduction band of the semiconductor fine particles 22 and further reach the conductive support 1 by diffusion. At this time, the molecules of the sensitizing dye 21 become oxidants; However, in the photoelectrochemical cell 100, the electrons on the electrode return to the oxide while working in the external circuit 6, where the light receiving electrode 5 works as the negative electrode of this battery.

The photoconductor layer 2 includes a porous semiconductor layer made of a layer of semiconductor fine particles 22 adsorbed with a dye, which will be described later. This pigment may be partially dissociated in the electrolyte. The photosensitive member layer 2 is designed according to the purpose, and can form a multilayered structure.

As mentioned above, the photosensitive member layer 2 contains the semiconductor microparticles | fine-particles 22 which the specific pigment | dye adsorb | sucked, and, thereby, light reception sensitivity is high. When used as the photoelectrochemical cell 100, high photoelectric conversion efficiency and high durability can be obtained.

(A) metal complex pigment

The photoelectric conversion element of this invention contains the semiconductor fine particle sensitized with the metal complex dye which has a structure represented by following formula (I). Moreover, the dye-sensitized solar cell of this invention contains this photoelectric conversion element.

In said formula (I), R <^1> and R <^2> respectively independently represents the group represented by either of following formula (II)-(VIII). R ¹ and R ² may be the same as or different from each other, but preferably R ¹ and R ² are the same as each other. R ¹ and R ² are each preferably a group represented by formula (II), a group represented by formula (VII) or a group represented by formula (VIII); More preferably, it is group represented by Formula (II) or group represented by Formula (VIII); Especially preferably, it is group represented by Formula (II).

In said formula (I), L <^1> and L <^2> respectively independently represents the group which consists of at least 1 sort (s) of group chosen from the group which consists of an ethenylene group, an ethynylene group, and an arylene group. L ¹ and L ² are conjugated with R ¹ or R ² and bipyridine. Here, the ethenylene group and the arylene group may be substituted or unsubstituted.

From the standpoint of suppression of lowering conversion efficiency due to undesired association between molecules, L1 and L2 are preferably conjugated chains composed of an ethenylene group and / or an ethynylene group. Ethenylene groups may be unsubstituted or substituted. L1 and L2 are each particularly preferably conjugated chains composed of ethenylene groups, and the ethenylene group may be unsubstituted or substituted. L1 and L2 are the conjugated chains which most preferably consist of unsubstituted ethenylene, respectively. When L1 and L2 are each such conjugated chains, the effect of expanding the light absorption region can be obtained by increasing the wavelength and increasing the molar extinction coefficient.

Substituted ethenylene groups are preferably methylethenylene, dimethylethenylene, methoxyethenylene, phenylethenylene, 4-methoxyphenylethenylene or trifluoromethylethenylene; More preferably methylethenylene, phenylethenylene or methoxyethylene; Especially preferably, it is methyl ethenylene.

The substituted or unsubstituted arylene group preferably has 6 to 50 nuclear atoms, more preferably 6 to 30 nuclear atoms, particularly preferably 6 to 18 nuclear atoms, and most preferably 6 to 12 nuclear atoms. Arylene group. In addition, when the conjugated chain includes carbon-carbon double bonds, each double bond may form the E isomer or the Z isomer, or may form a mixture of the E isomer and the Z isomer. In the present invention, the number of nuclear atoms means the number of atoms other than hydrogen atoms.

The conjugated chain containing an unsubstituted ethenylene group is preferably ethenylene or butadienylene; More preferably ethenylene.

Although the specific example of L1 and L2 is shown below, this invention is not limited to this.

In L-11 to L-13, n represents an integer of 1 to 5 and Me represents a methyl group.

In said formula (I), R <^3> and R <^4> represents a substituent each independently, and the following substituent W is mentioned as the example. As a substituent, Preferably, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, or an aryloxy group; More preferably, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group; Especially preferably, they are an alkyl group or an aryl group.

[Substituent W]

Examples of the substituents (hereinafter referred to as substituents W) include the following: Alkyl group [It represents a linear, branched, or cyclic substituted or unsubstituted alkyl group, and this is an alkyl group (preferably having 1 to C). An alkyl group of 30, for example methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, or 2-ethylhexyl), cycloalkyl group ( Preferably, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, for example cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably, substituted with 5 to 30 carbon atoms or An unsubstituted bicycloalkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example bicyclo [1.2.2] heptan-2-yl or bicyclo [2.2.2] Octane-3-yl), and three or more ring structures Tricyclo or more structure having; Alkyl group (for example, alkyl group of alkylthio group) in a substituent mentioned later also represents the alkyl group of this said concept]; Alkenyl groups [linear, branched or cyclic substituted or unsubstituted alkenyl groups, which include alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, for example vinyl, allyl, prenyl, Geranyl or oleyl), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group having one hydrogen atom removed from a cycloalkene having 3 to 30 carbon atoms, eg For example, 2-cyclopenten-1-yl or 2-cyclohexen-1-yl, and a bicycloalkenyl group (substituted or unsubstituted bicycloalkenyl group, preferably substituted or unsubstituted bicycloalcohol having 5 to 30 carbon atoms Kenyl groups, ie monovalent groups in which one hydrogen atom is removed from a bicycloalkene having one double bond, for example bicyclo [2.2.1] hept-2-en-1-yl or bicyclo [2.2.2 ] Oct- 2-en-4-yl); Alkynyl groups (preferably, substituted or unsubstituted alkynyl groups having 2 to 30 carbon atoms, such as ethynyl, propargyl, or trimethylsilylethynyl); Aryl groups (preferably substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, for example phenyl, 4-methoxyphenyl, p-tolyl, naphthyl, m-chlorophenyl, or o-hexadecanoylaminophenyl) ;

Heterocyclic groups (preferably monovalent groups wherein one hydrogen atom has been removed from a substituted or unsubstituted 5- or 6-membered aromatic or non-aromatic heterocyclic compound; more preferably, 5- to 30 carbon atoms) Or 6-membered aromatic heterocyclic groups such as 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl); Silyl groups (preferably, substituted or unsubstituted silyl groups having 3 to 30 carbon atoms such as trimethylsilyl, t-butyldimethylsilyl, or phenyldimethylsilyl); A hydroxyl group; Alkoxy groups (preferably substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, for example methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy or 2 Ethylhexyloxy); Aryloxy groups (preferably substituted or unsubstituted aryloxy groups having 6 to 30 carbon atoms, for example phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 4-hexyl Phenoxy, 2-tetradecanoylaminophenoxy); Heterocyclic oxy groups (preferably substituted or unsubstituted heterocyclic oxy groups having 2 to 30 carbon atoms, such as 1-phenyltetrazol-5-oxy, 2-tetrahydropyranyloxy); Silyloxy groups (preferably, silyloxy groups having 3 to 20 carbon atoms such as trimethylsilyloxy or t-butyldimethylsilyloxy); Acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, or substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, for example formyloxy, acetyl Oxy, pivaloyloxy, stearoyloxy, benzoyloxy or p-methoxyphenylcarbonyloxy); Carbamoyloxy groups (preferably substituted or unsubstituted carbamoyloxy groups having 1 to 30 carbon atoms, for example N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinoca Carbonyloxy, N, N-di-n-octylaminocarbonyloxy, or Nn-octylcarbamoyloxy);

Alkoxycarbonyloxy groups (preferably substituted or unsubstituted alkoxycarbonyloxy groups having 2 to 30 carbon atoms, for example, methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, or n Octylcarbonyloxy); Aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, for example, phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, or pn-hexa Decyloxyphenoxycarbonyloxy); Amino groups (preferably amino groups, substituted or unsubstituted alkylamino groups having 1 to 30 carbon atoms, or substituted or unsubstituted alinino groups having 6 to 30 carbon atoms, for example amino, methylamino, dimethylamino, anilin, N- Methyl-anilino, or diphenylamino); Acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, or substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, such as formylamino, acetylamino, Pivaloylamino, lauroylamino, benzoylamino, or 3,4,5-tri-n-octyloxyphenylcarbonylamino); Aminocarbonylamino groups (preferably substituted or unsubstituted aminocarbonylamino having 1 to 30 carbon atoms, for example carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonyl Amino, or morpholinocarbonylamino); Alkoxycarbonylamino groups (preferably substituted or unsubstituted alkoxycarbonylamino groups having 2 to 30 carbon atoms, for example methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxy Cycarbonylamino, or N-methyl-methoxycarbonylamino); Aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, for example phenoxycarbonylamino, p-chlorophenoxycarbonylamino, or mn-octyloxyphenoxyca Ribonylamino);

Imido groups (preferably N-succinimido or N-phthalimido); Aryl- or heterocyclic-azo groups (preferably substituted or unsubstituted aryl azo groups having 6 to 30 carbon atoms, or substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms, for example phenylazo, p-chlorophenylazo, Or 5-ethylthio-1,3,4-thiadiazol-2-ylazo); A mercapto group; Alkylthio groups (preferably substituted or unsubstituted alkylthio groups having 1 to 30 carbon atoms, for example methylthio, ethylthio, or n-hexadecylthio); Arylthio groups (preferably substituted or unsubstituted arylthio groups having 6 to 30 carbon atoms such as phenylthio, p-chlorophenylthio, or m-methoxyphenylthio); Heterocyclic thio groups (preferably substituted or unsubstituted heterocyclic thio groups such as 2-benzothiazolylthio or 1-phenyltetrazol-5-ylthio); Sulfo group; Alkyl- or aryl-sulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted arylsulfonyl groups having 6 to 30 carbon atoms, for example methylsulfonyl group, ethylsulfonyl group, phenyl Sulfonyl group or p-methylphenylsulfonyl group); Sulfamoyl groups (preferably substituted or unsubstituted sulfamoyl groups having 0 to 30 carbon atoms, such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl , N-acetylsulfamoyl, N-benzoylsulfamoyl, or N- (N'-phenylcarbamoyl) sulfamoyl); Sulfamoylamino groups (preferably substituted or unsubstituted sulfamoylamino groups having 0 to 30 carbon atoms such as sulfamoylamino, N, N-dimethylaminosulfonylamino, or N-n-octylaminosulfonylamino); Sulfino groups;

Alkyl- or aryl-sulfinyl groups (preferably substituted or unsubstituted alkylsulfinyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted arylsulfinyl groups having 6 to 30 carbon atoms, such as methylsulfinyl, ethylsulfinyl, Phenylsulfinyl, or p-methylphenylsulfinyl); Alkyl- or aryl-sulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino groups having 1 to 30 carbon atoms, or substituted or unsubstituted arylsulfonylamino groups having 6 to 30 carbon atoms, for example methylsulfonylamino, Butylsulfonylamino, phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, or p-methylphenylsulfonylamino); Acyl group (preferably a carbonyl group via a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, or a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms) Heterocyclic carbonyl groups bonded to, for example, acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, or 2-furylcarbonyl) ; A carboxyl group; Aryloxycarbonyl groups (preferably substituted or unsubstituted aryloxycarbonyl groups having 7 to 30 carbon atoms, for example phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, or pt-butylphenoxy Cycarbonyl); Alkoxycarbonyl groups (preferably substituted or unsubstituted alkoxycarbonyl groups having 2 to 30 carbon atoms, for example, methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, or n-octadecyloxycarbonyl); Carbamoyl groups (preferably substituted or unsubstituted carbamoyl groups having 1 to 30 carbon atoms, for example carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di- n-octylcarbamoyl or N- (methylsulfonyl) carbamoyl);

Phosphino groups (preferably substituted or unsubstituted phosphino groups having 2 to 30 carbon atoms, for example dimethylphosphino, diphenylphosphino or methylphenoxyphosphino); Phosphinyl groups (preferably substituted or unsubstituted phosphinyl groups having 2 to 30 carbon atoms, such as phosphinyl, dioctyloxyphosphinyl, or diethoxyphosphinyl); Phosphinyloxy groups (preferably substituted or unsubstituted phosphinyloxy groups having 2 to 30 carbon atoms such as diphenoxyphosphinyloxy or dioctyloxyphosphinyloxy); Phosphinylamino groups (preferably substituted or unsubstituted phosphinylamino groups having 2 to 30 carbon atoms, such as dimethoxyphosphinylamino or dimethylaminophosphinylamino); Phospho groups; Phosphonyl groups (preferably substituted or unsubstituted phosphonyl groups having 2 to 30 carbon atoms such as phosphonyl, octyloxyphosphinyl, methoxyphosphonyl, ethoxyphosphinyl); Phosphonyloxy groups (preferably substituted or unsubstituted phosphonyloxy groups having 2 to 30 carbon atoms such as phenoxyphosphonyloxy, octyloxyphosphonyloxy, or ethoxyphosphonyloxy); Phosphonylamino groups (preferably substituted or unsubstituted phosphonylamino groups having 2 to 30 carbon atoms such as methoxyphosphonylamino, or dimethylaminophosphonylamino);

Cyano; A nitro group; And halogen atoms (eg fluorine atoms, chlorine atoms, bromine atoms, or iodine atoms).

The substituent may be further substituted. In that case, the substituent W mentioned above can be mentioned as an example of a substituent.

In formula (I), n1 and n2 respectively independently represent the integer of 0-3. When n1 is an integer of 1 or more, R ³ may combine with L ¹ to form a ring. When n2 is an integer of 1 or more, R ⁴ may combine with L ² to form a ring. When n1 is two or more bulls, R ³ may be the same as or different from each other, or R ³ may be bonded to each other to form a ring. When n2 is an integer of 2 or more, R ⁴ may be identical to or different from each other, or R ⁴ may be bonded to each other to form a ring. When n1 and n2 are each an integer of 1 or more, R ³ and R ⁴ may be bonded to each other to form a ring. Preferred examples of these formed rings include benzene ring, pyridine ring, thiophene ring, pyrrole ring, furan ring, cyclohexane ring, and cyclopentane ring.

In formula (I), n3 and n4 respectively independently represent the integer of 0-3. When n3 is an integer greater than or equal to 2, A <^1> may mutually be same or different. When n4 is an integer greater than or equal to ² , A <^2> may mutually be same or different. n3 and n4 are each preferably integers of 0 to 2, more preferably 0 or 1. It is preferable that the sum of n3 and n4 is an integer of 0-2.

In Formula (I), A ¹ and A ² each independently represent an acid group or a salt thereof. In the present invention, the term " acidic group " means a group having a pKa value of 13 or less of the most acidic hydrogen atom among the hydrogen atoms constituting the acidic group. Examples of acidic groups include carboxylic acid groups (carboxyl groups), sulfonic acid groups, phosphonic acid groups, phenolic hydroxyl groups, alkylsulfonylamino groups, phosphoric acid groups, squaric acid groups, silicic acid groups and boric acid groups. Preferred examples include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups and phenolic hydroxyl groups; More preferred examples include carboxylic acid groups and sulfonic acid groups; Particularly preferred examples include carboxylic acid groups.

The counter ions of the above acidic groups are preferably protons, inorganic or organic ammonium ions, or alkali metal ions. As the alkali metal, sodium ions, potassium ions or lithium ions are preferable; More preferred are sodium ions or potassium ions; Sodium ions are particularly preferred. Examples of the inorganic or organic ammonium ions include ammonium ions and pyridinium ions. As inorganic or organic ammonium ion, ammonium ion and tertiary or quaternary alkylammonium ion are preferable; More preferred are tertiary or quaternary ammonium ions; Quaternary ammonium ions are particularly preferred. As quaternary ammonium ion, tetramethylammonium ion, tetraethylammonium ion, tetrabutylammonium ion, or tetrahexyl ammonium ion is preferable; More preferred are tetrabutylammonium ions or tetrahexylammonium ions; Tetrabutylammonium ions are particularly preferred.

In formulas (II) to (VI), R ⁵ , R ⁸ , R ¹³ , R ¹⁶ and R ¹⁹ each independently represent an alkynyl group or an aryl group. R ⁵ , R ⁸ , R ¹³ , R ¹⁶ and R ¹⁹ are each preferably an alkynyl group. Typically, the step of determining the most speed in the dye-sensitized solar cell is a reduction process of the dye from the redox system. A pigment | dye exists for a long time in an unstable monoelectron oxidation state, and leads to decomposition | disassembly of a pigment | dye.

By the presence of an alkynyl group and an aryl group, the effect that the reduction from a redox system such as iodine proceeds smoothly can be obtained. The triple bond portion of the alkynyl group is linear, and the? Electron cloud is uniformly positioned around 360 degrees of the portion, which can exert an effect of easily interacting with the redox system (iodine or the like) in the electrolyte. In addition, the aryl group is not as remarkable as in the case of an alkynyl group, but the π electron cloud can be spread to exert the same effect.

The alkynyl group is preferably an alkynyl group having 2 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, particularly preferably 5 to 18 carbon atoms, and most preferably 5 to 15 carbon atoms. The alkynyl group may be further substituted with a substituent W. As a substituent, Preferably, an alkyl group, an alkynyl group, an alkoxy group, an aryl group, an aryloxy group, or a heterocyclic group; More preferably, an alkyl group, an aryl group, or a heterocyclic group; Especially preferably, it is an alkyl group.

As an aryl group, Preferably, it is a C6-C30, More preferably, it is a C6-C18, Especially preferably, it is a C6-C12 aryl group. The aryl group may be further substituted with a substituent W. The substituent is preferably an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a heterocyclic group, an alkylthio group, an arylthio group or an amino group; More preferably, an alkyl group, an alkoxy group, an alkylthio group, or an amino group; Especially preferably, they are an alkoxy group or an amino group.

In formulas (II) to (VIII), R ⁶ , R ⁹ to R ¹² , R ¹⁴ , R ¹⁵ , R ¹⁷ , R ¹⁸ , R ²⁰ to R ²³ , R ²⁵ , R ²⁶ , and R ²⁸ to R ³¹ are Each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an amino group, a heterocyclic group or a halogen atom; At least one of R ²⁵ and R ²⁶ represents an alkyl group. As R ²⁵ and R ²⁶ , a hydrogen atom, an alkyl group, an alkoxy group and an amino group are preferable; More preferably a hydrogen atom and an alkyl group; Hydrogen atoms are particularly preferred. At least one alkyl group of R ²⁵ and R ²⁶ is preferably a branched or straight chain alkyl group having 1 to 12 carbon atoms, more preferably 3 to 10 carbon atoms, and particularly preferably 5 to 8 carbon atoms. That is, such a structure has the effect of suppressing the intermolecular association of the dye resulting in a decrease in the conversion efficiency, the effect of inhibiting the access of water which causes desorption of the dye from the oxide semiconductor, and the effect of the long wave due to the electron donation of the alkyl group. Can exert.

R ⁶ is preferably a hydrogen atom, an alkyl group, an alkynyl group or an alkoxy group; More preferably, they are a hydrogen atom or an alkyl group.

R ⁹ to R ¹² , R ²⁰ to R ²³ , and R ²⁸ to R ³¹ are each preferably a hydrogen atom or an alkyl group; More preferably, it is a hydrogen atom.

R ¹⁴ and R ¹⁷ are each preferably a hydrogen atom or an alkyl group; More preferably, it is a hydrogen atom.

R ¹⁵ and R ¹⁸ are each preferably a hydrogen atom, an alkyl group, an alkynyl group, an aryl group, an amino group, an alkoxy group or an alkylthio group; More preferably, a hydrogen atom, an alkyl group, or an alkynyl group; Especially preferably, they are an alkyl group or a hydrogen atom.

R ⁷ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or a halogen atom. R ⁷ is preferably a hydrogen atom, an alkyl group, an alkynyl group or an alkylthio group; More preferably, it is a hydrogen atom.

R <^7> is group adjacent to R <^5> mentioned above, and in order to acquire the above-mentioned effect, a three-dimensionally small thing is preferable. R ⁷ does not directly bond with a group having a hard unshared electron pair such as an oxygen atom (eg, an alkoxy group, an aryloxy group, etc.) in the 5-membered heterocycle of Formula (II). The reason for this is that the reduction of the pigment is not performed smoothly due to the electron repulsion with the redox system. In this case, R ⁷ may be bonded to a group having a soft unshared electron pair such as a sulfur atom.

Any of R ⁶ and R ⁷ , R ⁹ to R ¹² , any of R ¹⁴ and R ¹⁵ , R ¹⁷ and R ¹⁸ , R ²⁰ to R ²³ , any of R ²⁵ and R ²⁶ , and R ²⁸ to R ³¹ Each may combine with each other to form a ring. The ring formed by each bond of R ⁹ to R ¹² , R ¹⁴ and R ¹⁵ , R ¹⁷ and R ¹⁸ , R ²⁰ to R ²³ , R ²⁵ and R ²⁶ , and R ²⁸ to R ³¹ is preferably 5- To 10-membered rings, more preferably 5- to 8-membered rings, particularly preferably 5- or 6-membered rings.

Examples of the 5-membered ring include cyclopentane ring, tetrahydrofuran ring, 1,3-dioxolane ring, 1,3-oxathiolane, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thia Sol ring, pyrazole ring, isoxazole ring and isothiazole ring. Among these, cyclopentane ring, 1,3-dioxolane ring, tetrahydrofuran ring and thiophene ring are preferable; More preferred are cyclopentane ring and 1,3-dioxolane ring; Cyclopentane rings are particularly preferred.

Examples of the 6-membered ring include cyclohexane ring, benzene ring, pyran ring, dihydropyran ring, dioxane ring, pyridine ring, pyrazine ring, piperidine ring, piperazine ring, and morpholine ring. Among these, cyclohexane ring, benzene ring, dihydropyran ring, dioxane ring and piperazine ring are preferable; More preferred are cyclohexane ring and benzene ring; Particular preference is given to cyclohexane rings.

Among the groups which do not form a ring, preferred examples include a hydrogen atom, an alkyl group, an alkoxy group and an aryl group; More preferred examples include hydrogen atom, alkyl group and alkoxy group; Particularly preferred examples include hydrogen atoms.

In formulas (VII) and (VIII), two R ²⁴ and two R ²⁷ present in the same property group may be the same or different from each other, and R ²⁴ and R ²⁷ may each be a hydrogen atom, an alkyl group, an alkenyl group, or an alkoxy group. It represents a nil group. On the other hand, a plurality of R ²⁴ and a plurality of R ²⁷ are not bonded to each other to form a ring. The presence of these hydrophobic groups has the effect of inhibiting the access of water, which is present in a small amount in the electrolyte, leading to a decrease in durability due to desorption of the dye. Aromatic groups such as a benzene ring may cause inefficient association of pigments with each other by stacking of? -Electrons, which may cause a decrease in conversion efficiency. However, these aliphatic groups have a high degree of freedom and can suppress inefficient association, which is effective for improving conversion efficiency.

R ²⁴ and R ²⁷ are each preferably an alkyl group, an alkenyl group or an alkynyl group; More preferably, an alkyl group or an alkynyl group; Especially preferably, it is an alkyl group.

The alkyl group is preferably a branched or straight chain alkyl group having 1 to 15 carbon atoms, more preferably 3 to 12 carbon atoms, and particularly preferably 4 to 10 carbon atoms.

Alkenyl groups and alkynyl groups are preferably 2 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, particularly preferably 6 to 10 carbon atoms.

M1 to m6 each independently represent an integer of 1 to 5 in formulas (II) to (VIII).

Y represents S, O, Se, Te or NR ³² ; R ³² represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group.

X represents S, Se, Te, NR ³² ; R ³² represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group.

As Y, preferably S, O or NR ³² ; More preferably S or O; Especially preferably, it is S. In the case where Y is S, the thiophene ring formed is considered to have high electron donating effect, long wave effect, and high stability against many nucleophiles present in the electrolyte.

X is preferably S, Se or NR ³² ; More preferably S or Se; Especially preferably, it is S. Selecting S as X is preferable for the same reason as Y and from the viewpoint of improving the reduction rate of the dye due to interaction with the redox system of the orbit of the soft S atom.

R ³² is preferably a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group; More preferably, a hydrogen atom or an alkyl group; Especially preferably, it is an alkyl group.

Although the specific example of the ligand represented by said formula (I) is shown below, this invention is not limited to this. As these acidic groups, only proton non-liforme is shown, but these acidic groups may each be a proton dissociation body. If there is a carbon-carbon double bond in the structure, E isomers or Z isomers, or mixtures thereof can be used.

It is preferable that the metal complex dye of this invention is represented by following formula (IX).

M (LL1) (LL2) ( Z) p · CI formula (IX)

In formula (IX), M represents a metal atom. M is preferably a metal capable of 4- or 6-coordination (eg Ru, Re, Rh, Pt, Fe, Os, Cu, Ir, Pd, W, Co, Zn, Pb); More preferably Ru, Re, Rh, Pt, Fe, Os, Cu, Ir, Pd, W or Co; Particularly preferably Ru, Re, Rh, Os, Ir or W; Most preferably Ru.

In formula (IX), LL1 has the same meaning as formula (I), and the preferred range thereof is also the same. In formula (IX), LL2 represents the ligand represented by the following formula (X).

In formula (X), R ³³ and R ³⁴ each independently represent a substituent, and examples thereof include the substituent W described above. As a substituent, Preferably, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, or a halogen atom; More preferably, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group; Especially preferably, they are an alkyl group or an aryl group.

In formula (X), n5 and n6 respectively independently represent the integer of 0-3. When n5 is an integer of 2 or more, R ³⁴ may be identical to or different from each other, or R ³⁴ may combine with each other to form a ring. When n6 is an integer of 2 or more, R ³³ may be the same as or different from each other, or R ³³ may be bonded to each other to form a ring. When n5 and n6 are each an integer of 1 or more, R ³³ and R ³⁴ may combine with each other to form a ring. Preferred examples of these formed rings include benzene ring, pyridine ring, thiophene ring, pyrrole ring, furan ring, cyclohexane ring and cyclopentane ring.

In formula (X), n7 and n8 respectively independently represent the integer of 1-4. When n7 is an integer of 2 or more, A ³ may be identical to or different from each other. When n8 is an integer greater than or equal to 2, A <^4> may mutually be same or different. n7 and n8 are each preferably an integer of 1 to 3, more preferably an integer of 1 or 2, particularly preferably an integer of 1.

In Formula (X), A <^3> and A <^4> are synonymous with A <^1> and A <^2> in Formula (I), and its preferable range is also the same. Substituent positions for A ³ and A ⁴ are preferably at the m-position or p-position, more preferably at the p-position of the nitrogen atom of the pyridine ring.

Although the specific example of LL2 is shown below, this invention is not limited to these. Although these acidic groups show only proton derivatized bodies, these acidic groups may each be proton dissociates. When there are carbon-carbon double bonds present in the structure, E isomers or Z isomers, or mixtures thereof can be used.

In addition, Ph represents a phenyl group.

In formula (IX), Z represents a single- or double-dented ligand. In addition, p represents the integer of 0-2. In the case of a metal in which M is easy to form four coordination such as Cu, Pd, Pt, Zn or Pb, p is preferably 0. In the case where M in formula (IX) is a metal that is liable to form a 6-coordination, p is preferably 2 when Z is a monodentate ligand; P is preferably 1 when Z is a bidentate ligand. When p is 2, Z may be identical to or different from each other.

Ligand Z is an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms, for example, acetyloxy group, benzoyloxy group, salicylic acid group, glycyloxy group, N, N-dimethylglyciyloxy group, oxalylene group ( -OC (O) C (O) O-), etc.), acylthio group (preferably acylthio group having 1 to 20 carbon atoms, for example, acetylthio group, benzoylthio group, etc.), thioacyloxy group (preferably Preferably a thioacyloxy group having 1 to 20 carbon atoms, for example, a thioacetyloxy group (CH ₃ C (S) O-) and the like), a thioacylthio group (preferably a thioacylthio group having 1 to 20 carbon atoms, For example, thioacetylthio group (CH ₃ C (S) S-), thiobenzoylthio group (PhC (S) S-), etc.), acylaminooxy group (preferably acylaminooxy group having 1 to 20 carbon atoms) For example, N-methylbenzoylaminooxy group (PhC (O) N (CH ₃ ) O-), acetylaminooxy group (CH ₃ C (O) NHO-), etc.), thiocarbamate group (preferably Burnt Thiocarbamate groups having 1 to 20 carbon atoms, such as N, N-diethylthiocarbamate groups, dithiocarbamate groups (preferably dithiocarbamate groups having 1 to 20 carbon atoms, For example, N-phenyldithio carbamate group, N, N-dimethyldithiocarbamate group, N, N-diethyldithiocarbamate group, N, N-dibenzyldithiocarbamate group Etc.), a thiocarbonate group (preferably a thiocarbonate group having 1 to 20 carbon atoms, for example, an ethylthiocarbonate group, etc.), a dithiocarbonate group (preferably having 1 to 20 carbon atoms) Oka Viterbo carbonate groups such as ethylthio carbonate group (C ₂ H ₅ OC (S) S-), etc.), tri-thiocarbonate group (preferably tree thiocarbonate group having 1 to 20 carbon atoms such as ethyl tree thiocarbonate group (C ₂ H ₅ SC (S) S-) and the like), an acyl group (preferably having 1 to 20 carbon atoms Acyl groups such as acetyl group, benzoyl group), selenocyanate group, isocelenocyanate group, thiocyanate group, isothiocyanate group, cyanate group, isocyanate group, isocyano group, cya Furnace group, alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, such as methanethio group, ethylenedithio group, etc.), arylthio group (preferably an arylthio group having 6 to 20 carbon atoms, for example Benzenethio group, 1,2-phenylenedithio group and the like), alkoxy group (preferably alkoxy group having 1 to 20 carbon atoms, for example methoxy group) and aryloxy group (preferably having 6 to 20 carbon atoms) Single or bidentate ligands coordinated through a coordinating group selected from the group consisting of oxy groups such as phenoxy groups, quinoline-8-hydroxyl groups, or halogen atoms (preferably chlorine atoms, bromine atoms, iodine atoms, etc.) ), Carbonyl (…) CO); Dialkyl ketones (preferably dialkyl ketones having 3 to 20 carbon atoms, for example acetone ((CH ₃ ) ₂ CO ...), etc.), 1,3-diketones (preferably 1,3 having 3 to 20 carbon atoms) -Diketones such as acetylacetone (CH ₃ C (O ...) CH = C (O-) CH ₃ ), trifluoro acetylacetone (CF ₃ C (O ...) CH = C (O-) CH ₃ ), Dipyvaloyl methane (tC ₄ H ₉ C (O ...) CH = C (O-) tC ₄ H ₉ ), dibenzoylmethane (PhC (O ...) CH = C (O-) Ph), 3- Chloroacetylacetone (CH ₃ C (O ...) CCl = C (O-) CH ₃ ), etc.), a carbonamide group (preferably a carbonamide group having 1 to 20 carbon atoms, for example CH ₃ N = C) (CH ₃ ) O-, -OC (= NH) -C (= NH) O- and the like), thiocarbonamide group (preferably thiocarbonamide group having 1 to 20 carbon atoms, for example CH ₃ N) = C (CH ₃ ) S- or the like), or thiourea (preferably thiourea having 1 to 20 carbon atoms, for example (NH (...) = C (S-) NH ₂ , CH ₃ N (...) =)). A ligand consisting of C (S-) NH CH ₃ , (CH ₃ ) 2 N-C (S ...) N (CH ₃ ) _2, etc.) "..." represents a coordination bond with the metal atom M. As shown in FIG.

Ligand Z is preferably an acyloxy group, thioacylthio group, acylaminooxy group, dithiocarbamate group, dithiocarbonate group, trithiocarbonate group, selenocyanate group, iso seleno A coordination group selected from the group consisting of a cyanate group, a thiocyanate group, an isothiocyanate group, a cyanate group, an isocyanate group, an isocyano group, a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group Or a ligand composed of a halogen atom, carbonyl, 1,3-diketone or thiourea, and more preferably an acyloxy group, acylaminooxy group, dithiocarbamate group, and selenocyanate Group, isocelenocyanate group, thiocyanate group, isothiocyanate group, cyanate group, isocyanate group, isocyano group, cyano group and arylthio group That is a ligand coordinated through the selected times crisis from the group, or a halogen atom, a 1,3-diketone or thiourea ligands consisting of a; More preferably, it consists of a dithiocarbamate group, a selenocyanate group, an isocelenocyanate group, a thiocyanate group, an isothiocyanate group, a cyanate group, an isocyanate group, an isocyano group, and a cyano group. A ligand coordinating through a coordinating group selected from the group, or a ligand consisting of a halogen atom or 1,3-diketone; Especially preferably, through a coordinating group selected from the group consisting of dithiocarbamate group, selenocyanate group, isocelenocyanate group, thiocyanate group, isothiocyanate group, cyanate group and isocyanate group A ligand to be coordinated or a ligand consisting of a halogen atom or 1,3-diketone; Most preferably, it is a ligand coordinated through the coordinating group selected from the group which consists of an isocelenocyanate group, an isothiocyanate group, and an isocyanate group from an electron donating viewpoint.

If the ligand Z comprises an alkyl group, an alkenyl group, an alkynyl group, an alkylene group, or the like, these groups may be linear or branched and may be substituted or unsubstituted. When the ligand Z includes an aryl group, heterocyclic group, cycloalkyl group, or the like, these groups may be substituted or unsubstituted and may be monocyclic or condensed rings.

When the ligand Z is a bidentate ligand, Z is an acyloxy group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate Ligands coordinated through a coordinating group selected from the group consisting of a group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or 1,3-dike It is preferable that it is a ligand which consists of a ton, a carbonamide group, a thiocarbonamide group, or a thiourea.

When Z is a monodentate ligand, Z is a selenocyanate group, isocelenocyanate group, thiocyanate group, isothiocyanate group, cyanate group, isocyanate group, cyano group, alkylthio group and arylthio group It is preferable that it is a ligand which coordinates through the coordinating group selected from the group which consists of, or the ligand which consists of a halogen atom, carbonyl, dialkyl ketone, or thiourea.

Although the specific example of ligand Z is shown below, this invention is not limited to these. In addition, the structural formula shown below is just one reference structure among the resonance structures which can take various structures, and the distinction between covalent bond (denoted by-) and coordination bond (denoted by ...) is also formal, no.

CI in Formula (IX) represents counter ion when counter ion is needed to neutralize an electric charge. The pigments, whether cationic or anionic, or having a net ionic charge, depend on the metals, ligands and substituents in the pigments. When the substituent has a dissociable group such as an acid group, the dye may have a dissociated negative charge. In this case, the charge of the whole molecule is neutralized by CI.

Positive counter ions are the same as the counter ions of A ¹ and A ² which represent acidic groups.

The negative counter ions can be inorganic and organic anions. Examples include halogen anions (eg fluoride ions, chloride ions, bromide ions, iodide ions, etc.), substituted arylsulfonate ions (eg p-toluene sulfonate ions, p-chlorobenzene sulfonate ions, etc.) Aryldisulfonate ions (e.g., 1,3-benzene disulfonate ions, 1,5-naphthalene disulfonate ions, 2,6-naphthalene disulfonate ions, etc.), alkylsulphate ions (e.g. Methyl sulfate, etc.), sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, picrate ion, acetate ion, and trifluoromethane sulfonate ion. Alternatively, as the charge balance counter ion, it is possible to use an ionic polymer or another dye having a charge opposite to the main dye. Alternatively, metal complex ions (for example bisbenzene-1,2-dithiolactone nickel (III) and the like) can be used.

It is preferable that ligand LL2 is a ligand represented by following formula (XI).

In Formula (XI), A ⁵ and A ⁶ each independently represent an acid group or a salt thereof. Examples of the acidic group include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, phenolic hydroxyl groups, alkylsulfonylamino groups, phosphoric acid groups, squaric acid groups, silicic acid groups, and boric acid groups. Preferred examples include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups and phenolic hydroxyl groups; More preferred examples include carboxylic acid groups and sulfonic acid groups; Particularly preferred examples include carboxylic acid groups.

In formula (XI), R ³⁵ and R ³⁶ each independently represent a substituent, and examples thereof include the substituent W described above. As a substituent, Preferably, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, or a halogen atom; More preferably, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group; Especially preferably, they are an alkyl group or an aryl group.

In formula (XI), n9 and n10 each independently represent an integer of 0 to 3, and when n9 is an integer of 2 or more, R ³⁵ may be the same as or different from each other, or R ³⁵ may be bonded to each other to form a ring. . When n10 is an integer of 2 or more, R ³⁶ may be identical to or different from each other, or R ³⁶ may combine with each other to form a ring. When n9 and n10 are each an integer of 1 or more, R ³⁵ and R ³⁶ may combine with each other to form a ring. Preferred examples of these formed rings include benzene ring, pyridine ring, thiophene ring, pyrrole ring, furan ring, cyclohexane ring and cyclopentane ring.

n9 and n10 are each preferably an integer of 0 to 3, more preferably an integer of 0 or 1, particularly preferably 0.

The ligand LL2 is preferably represented by the following formula (XII).

In formula (XII), A ⁷ and A ⁸ each independently represent an acid group or a salt thereof. Examples of the acidic group include carboxylic acid groups (carboxyl groups), sulfonic acid groups, phosphonic acid groups, phenolic hydroxyl groups, alkylsulfonylamino groups, phosphoric acid groups, squaric acid groups, silicic acid groups and boric acid groups. Preferred examples include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups and phenolic hydroxyl groups; More preferred examples include carboxylic acid groups and sulfonic acid groups; Particularly preferred examples include carboxylic acid groups.

The metal complex dye represented by the formula (IX) is preferably represented by any one of the following formulas (XIII) to (XV), more preferably formula (XIII) or formula (XV); Especially preferably, it is Formula (XIII).

In formulas (XIII) to (XV), A ⁹ , A ¹⁰ , A ¹¹ , A ¹² , A ^13, and A ¹⁴ each independently represent a carboxyl group or a salt thereof.

R ²⁰⁰ and R ²⁰³ have the same meaning as R ⁵ in formula (II), and the preferred range thereof is also the same. R ²⁰¹ and R ²⁰⁴ have the same meaning as R ⁷ in formula (II), and the preferred range thereof is also the same. R ²⁰² and R ²⁰⁵ have the same meanings as R ⁶ in formula (II), and the preferred range thereof is also the same. R ²⁰⁷ , R ²⁰⁸ , R ²¹⁰ and R ²¹ have the same meanings as R ²⁵ in formula (VII) and have the same preferred range. R ²¹³ to R ²¹⁶ and R ²¹⁸ to R ²²¹ have the same meanings as R ²⁸ in formula (VIII), and the preferred range thereof is also the same.

Here, at least one of R ²⁰⁷ and R ²⁰⁸ is an alkyl group, and at least one of R ²¹⁰ and R ²¹¹ is an alkyl group. The range with preferable alkyl group containing at least 1 is the same as the range in the case of Formula (II)-(VIII).

R ²⁰¹ and R ²⁰² , R ²⁰⁴ and R ²⁰⁵ , R ²⁰⁷ and R ²⁰⁸ , R ²¹⁰ and R ²¹¹ , any of R ²¹³ to R ²¹⁶ and any of R ²¹⁸ to R ²²¹ may combine with each other to form a ring. . The range preferable as a ring to form is the same as the range in the case of Formula (II)-Formula (VIII).

R ²⁰⁶ and R ²⁰⁹ have the same meaning as R ²⁴ in formula (VII), and the preferred range thereof is also the same. R ²¹² and R ²¹⁷ have the same meaning as R ²⁷ in formula (VIII), and the preferred range thereof is also the same.

m7 to m10 each independently represent an integer of 1 to 5;

Z represents a single or bidentate ligand, has the same meaning as Z in formula (IX), and the preferred range thereof is also the same.

q1-q3 respectively independently represent the integer of 1 or 2, Preferably it is 2.

The metal complex dye represented by the formula (XIII) is adsorbed onto the surface of the oxide semiconductor via A ⁹ or A ¹⁰ . In particular, R ⁵ is located on the electrolyte side on the side opposite to the oxide semiconductor surface seen spatially from the dye. Therefore, a smooth reduction effect from a redox system can be expected. In Formula (XV), an ethylenedioxy group having a high electron donation is bonded to the thiophene ring, whereby the potential of HOMO of the dye shifts negatively, and the binding contributes to the long wave.

The metal complex dye of the present invention is a solvent, preferably an organic solvent or a mixed solvent of an organic solvent and water, more preferably a THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solvent, methanol or The maximum absorption wavelength at the longest wave side in the solution when dissolved in ethanol, in particular in THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solvent, is preferably in the range of 350 to 1200 nm. More preferably, it is the range of 400-900 nm, Especially preferably, it is the range of 450-700 nm. The mixing ratio of THF and water is expressed by volume ratio.

Although the specific example of the metal complex dye represented by Formula (IX) below is shown, this invention is not limited to these. As these acidic groups, only proton non-lysates are shown, but these acidic groups may each be a proton dissociation body or may have the above-mentioned counter ion. Where there are carbon-carbon double bonds in the structure, these compounds may be E isomers or Z isomers, or mixtures thereof, or may be isomers such as cis isomers, trans isomers, or optically active materials, but are not particularly limited. , Single isomers or mixtures thereof.

Metal complex pigment | dye containing ligand LL1 which has a structure represented by Formula (I) which concerns on this invention is J. Am. Chem. Soc., 121, 4047 (1997), Can. J. Chem., 75, 318 (1997), Inorg. Chem., 27, 4007 (1988) et al. And the methods cited therein may be synthesized. In particular, the change of the counter cation can be freely changed the type of cation by treating the cation with a base and dissolving it, as shown in the synthesis example, and furthermore, by adjusting the pH from the amount of acidic reagent used, counter cations other than protons You can adjust the amount.

Preferred examples of the base to be used include tetraalkylammonium hydroxide and metal hydroxide.

When using the metal complex dye of this invention for the photoelectric conversion element mentioned later, the said pigment can be used individually or in combination with another pigment | dye. Among other dyes, at least one dye (preferably, a dye other than a metal complex dye having a ligand LL1 represented by formula (I) according to the present invention, and a dye used in combination) has a maximum absorption wavelength at the longest wave side. It is preferably at least 600 nm in a THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution.

Compared with the metal complex pigment | dye which has ligand LL1 represented by Formula (I) which concerns on this invention, by combining with the pigment | dye which photoelectrically converts on the long wave side more efficiently, it is possible to efficiently photoelectrically convert sunlight. As a combination pigment, Preferably a porphyrin pigment, a squarylium pigment, or a phthalocyanine pigment; More preferably porphyrin pigment or squarylium pigment; Especially preferably, it is a squarylium pigment | dye. Among the porphyrin pigments, binuclear complexes are preferred. Among the squarylium pigments, bis squarylium having two squarylium skeletons is preferable.

In this invention, when using a pigment | dye for the photoelectric conversion element mentioned later, it is preferable to use a coadsorption agent for the metal complex pigment | dye of this invention or the pigment used together. As such a coadsorption agent, the coadsorption agent which has a carboxyl group or its salt is preferable, The compound which has a fatty acid and a steroid skeleton as an example of this coadsorption agent is mentioned.

Fatty acids may be saturated or unsaturated fatty acids. Examples include butanoic acid, hexanoic acid, octanoic acid, decanoic acid, hexadecanoic acid, dodecanoic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid.

Examples of compounds having a steroid backbone include cholic acid, glycocholic acid, kenodeoxycholic acid, hicolic acid, deoxycholic acid, lithocholic acid and ursodeoxycholic acid. Among them, preferred are cholic acid, deoxycholic acid and kenodeoxycholic acid, and more preferably kenodeoxycholic acid.

Preferred coadsorbents are compounds represented by the following formula (XVI).

In formula (XVI), Ra represents the alkyl group which has only one acidic group or its salt. Rb represents a substituent, and the substituent W mentioned above is mentioned as an example. And n represents an integer of 0 or more. When n is an integer of 2 or more, a plurality of Rb may be the same or different from each other. Examples of such specific compounds include compounds exemplified as the compounds having the above-mentioned steroid backbone.

The coadsorbent which can be used in the present invention exhibits the effect of suppressing inefficient association of dyes by adsorbing to the semiconductor fine particles and preventing the reverse electron transfer from the oxide semiconductor surface to the redox system in the electrolyte.

[Photoelectric Conversion Element and Dye-Sensitized Solar Cell]

As shown in FIG. 1, the photoelectric conversion element 10 of the present invention includes a conductive support 1; A photoconductor layer (semiconductor film or semiconductor layer) 2 having porous semiconductor fine particles to which the metal complex dye (color 21) of the present invention adsorbed, which is provided on the conductive support 1; Charge carrier layer (which may also function as a hole transport layer) (3); And counter electrode 4. The conductive support provided with the semiconductor film functions as a working electrode in the photoelectric conversion element. In this embodiment, this photoelectric conversion element 10 is being operated as a dye-sensitized solar cell 100 by making it possible to use the battery in a battery which allows the battery to work by the external circuit 6.

In this embodiment, the light receiving electrode 5 includes a conductive support 1; And the photoconductor layer 2 containing the semiconductor fine particles 22 to which the dye compound 21 is adsorbed, which is applied onto the conductive support. In the present embodiment, the electrolyte is included in the light receiving electrode 5, but it is included in either or both of the photoconductor layer 2 and the charge carrier layer 3. The photosensitive member layer 2 may be designed according to the purpose and may be a single layer construction or a multilayer construction. The pigment compound (21) in one layer of the photosensitive member layer may be one kind or a mixture of plural kinds, and the metal complex dye of the present invention described above is used as at least one kind of the compound. Light incident on the photoconductor layer 2 excites the dye. The dye has electrons with high energy, and these electrons move from the dye compound 21 to the conduction band of the semiconductor fine particles 22 and further reach the conductive support 1 by diffusion. Wherein the metal complex dye is an oxidant; In the dye-sensitized solar cell, the electrons on the electrode return to the oxide of the dye while working in the external circuit 6, where the dye-sensitized photoelectric conversion element works as the cathode of the cell. In the present invention, materials used in the photoelectric conversion elements and the dye-sensitized solar cells and methods for producing each member can be used in the art, and the materials and methods are described, for example, in US Pat. No. 4,927,721, US Patent 4,684,537, U.S. Patent 5,084,365, U.S. Patent 5,350,644, U.S. Patent 5,463,057, U.S. Patent 5,525,440, JP-A-7-249790, JP-A-2004-220974 and JP- See A-2008-135197. Hereinafter, a main member is demonstrated suitably.

The conductive support is a support made of glass or a polymer material having a conductive layer on its surface or a conductive material such as a metal. As the support, in addition to glass and plastic, ceramics (JP-A-2005-135902), conductive resins (JP-A-2001-160425) and the like can be used. An optical management function can be provided to a support body, for example, the anti-reflection film which alternately laminated the high refractive index film | membrane of JP-A-2003-123859, and the low refractive index oxide film, and JP-A-2002- The light guide function of 260746 is mentioned.

It is preferable that the thickness of a conductive film layer is 0.01-30 micrometers, More preferably, it is 0.03-25 micrometers, Especially preferably, it is 0.05-20 micrometers.

It is preferable that the conductive support is substantially transparent. The term "substantially transparent" means that the light transmittance is at least 10%, preferably at least 50%, particularly preferably at least 80%. As a transparent conductive support body, the support body which apply | coated and formed electroconductive metal oxide to glass or plastic is preferable. In this case, the application amount of the conductive metal oxide is preferably 0.1 to 100 g per 1 m ² of glass or plastic support. When using a transparent conductive support, it is preferable that light enters from the support side.

As the semiconductor fine particles, fine particles of metal chalcogenides (for example, oxides, sulfides and selenides) or fine particles of perovskite can be preferably used. Preferred examples of chalcogenides of metals include oxides of titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium or tantalum, cadmium sulfide, and cadmium selenide. have. Preferred examples of perovskite include strontium titanate and calcium titanate. Among these, titanium oxide, zinc oxide, tin oxide, and tungsten oxide are particularly preferable.

Examples of the crystal structure of titania include anatase type, brookite type and rutile type structures, and anatase type and brookite type structures are preferable in the present invention. Titania nanotubes / nanowires / nanorods can be mixed with titania particulates or used as semiconductor electrodes.

The particle diameter of the semiconductor fine particles is expressed as an average particle diameter using a diameter when converting the projected area into a circle, preferably 0.001 to 1 m as the primary particles and 0.01 to 100 m as the average particle diameter of the dispersion. As a method of apply | coating a semiconductor fine particle on a conductive support body, a wet method, a dry method, or another method is mentioned.

It is preferable to form a short circuit prevention layer between a transparent conductive film and a photosensitive member layer (oxide semiconductor layer), in order to prevent reverse current by direct contact between electrolyte solution and an electrode. It is preferable to use a spacer or a separator to prevent contact between the light receiving electrode and the counter electrode. It is preferable that semiconductor microparticles | fine-particles have a large surface area so that a large amount of pigment | dye may be adsorb | sucked on a surface. For example, in the state which apply | coated the semiconductor fine particle on the support body, it is preferable that it is 10 times or more with respect to a projection area, and it is more preferable that it is 100 times or more. Although the upper limit of this value is not specifically limited, Usually, the upper limit is about 5000 times. In general, when the thickness of the semiconductor fine particle layer is large, the amount of dye that can be supported per unit area increases, so that the light absorption efficiency is increased. However, as the diffusion distance of the generated electrons increases, the loss due to charge recombination also increases. The preferred thickness of the semiconductor fine particle layer may vary depending on the use of the device, but the thickness is typically 0.1 to 100 μm. When using a photoelectric conversion element as a dye-sensitized solar cell, it is preferable that it is 1-50 micrometers, and, as for the thickness of a semiconductor fine particle layer, it is more preferable that it is 3-30 micrometers. The semiconductor fine particles may be calcined for 10 minutes to 10 hours at a temperature of 100 to 800 ° C. after application to the support to cause the particles to aggregate. In the case of using a glass support, the film formation temperature is preferably 400 to 60 ° C.

The coating amount per 1 m ² of the support of the semiconductor fine particles is preferably 0.5 to 500 g, more preferably 5 to 100 g. The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, particularly preferably 0.1 to 10 mmol, per m ² of the support. In this case, it is preferable to adjust the usage-amount of the pigment | dye of this invention to 5 mol% or more. As for the adsorption amount of a pigment | dye with respect to the semiconductor fine particle, 0.001-1 mmol is preferable with respect to 1 g of semiconductor fine particles, More preferably, it is 0.1-0.5 mmol. By adjusting the dye amount in such a range, the sensitization effect in a semiconductor can fully be acquired. On the other hand, if the amount of the dye is too small, the sensitization effect is insufficient. If the amount of the dye is too large, the portion of the dye that is not attached to the semiconductor is suspended, which causes a decrease in the sensitizing effect. It is preferable that the pigment | dye adsorption to an oxide semiconductor is single layer adsorption. If multilayer adsorption occurs, the electrons cannot be efficiently injected into the oxide semiconductor and the conversion efficiency is lowered. When the ligand which does not have an acidic group acting as an anchor when adsorbed to an oxide semiconductor has a group such as an alkyl group or an alkynyl group in the dye, self-organization is efficiently performed to promote monolayer adsorption. A colorless compound can be co-adsorbed for the purpose of reducing the interaction between pigment molecules such as association. Examples of the hydrophobic compound to be co-adsorbed include the co-adsorbents described above. When the metal complex dye containing the ligand LL1 having the structure represented by the formula (I) according to the present invention is a salt, the counter ion of the metal complex dye containing the ligand LL1 having the structure represented by the formula (I) is not particularly limited. Do not. Examples thereof include alkali metal ions and quaternary ammonium ions.

After adsorb | sucking a pigment | dye, an amine can be used to process the surface of semiconductor fine particles. Preferred amines include 4-tert-butylpyridine and polyvinylpyridine. These liquids can be used as they are, or can be used in a state dissolved in an organic solvent. The charge transfer layer is a layer having a function of supplementing electrons to the oxidant of the dye, and is formed between the light receiving electrode and the counter electrode. Representative examples of the material for forming the charge transfer layer include a so-called gel electrolyte obtained by impregnating a liquid prepared by dissolving a redox pair in an organic solvent and a liquid prepared by dissolving a redox pair in an organic solvent, and The molten salt containing a redox pair is mentioned.

Instead of the liquid electrolyte and the quasi-solid electrolyte described above, a solid charge transport system such as a p-type semiconductor or hole transport material may also be used. As the solid charge transport layer, an organic hole transport material can be used.

Since the redox pair becomes a carrier of the electrons, a certain concentration is required. Preferable total concentration is 0.01 mol / L or more, More preferably, it is 0.1 mol / L or more, Especially preferably, it is 0.3 mol / L or more. Although there is no restriction | limiting in particular in the upper limit in this case, Usually, it is about 5 mol / L.

The counter electrode is an electrode that works as an anode of a photoelectrochemical cell. The counter electrode usually has the same meaning as the above-described conductive support, but the support is not necessarily required in a configuration in which strength is easily maintained. The preferable structure of the counter electrode is a structure having high current collecting effect. In order for light to reach the photoconductor layer, at least one of the above-described conductive support and counter electrode must be substantially transparent. In the photoelectrochemical cell of this invention, it is preferable that a conductive support body is transparent and can inject sunlight from a support body side. In this case, it is more preferable that the counter electrode has a property of reflecting light. As the counter electrode of the photoelectrochemical cell, a glass or plastic plate on which a metal or conductive oxide is deposited is preferable, and a glass plate on which platinum is deposited is particularly preferable. In a photoelectrochemical cell, in order to prevent evaporation of components, it is preferable to seal the side surface of a battery with a polymer, an adhesive agent, etc. The characteristics of the photoelectrochemical cell of the present invention thus obtained are, in general, 100 mW / cm ² operation at AM 1.5 G, open circuit voltage 0.01 to 1.5 V, short circuit current density 0.001 to 20 mA / cm ² , shape factor 0.1 to 0.9, and conversion efficiency of 0.001 to 25%.

Example

<Example Preparation of Pigment>

(Example Preparation of Compound D-1-1a)

Exemplary pigment D-1-1a was prepared according to the method given in the scheme below.

(i) Preparation of Compound d-1-2

25 g of compound d-1-1, 33.8 g of Pd (dba), 8.6 g of triphenylphosphine, 2.5 g of copper iodide, and 25.2 g of 1-heptin were added to 70 mL of triethylamine and 50 mL of tetrahydrofuran. The obtained mixture was stirred at room temperature and stirred at 80 ° C. for 4.5 hours. After concentration, 26.4 g of compound d-1-2 was obtained by purification by column chromatography.

(ii) Preparation of Compound d-1-4

6.7 g of compound d-1-3 was dissolved in 200 mL of THF (tetrahydrofuran) at -15 ° C under a nitrogen atmosphere, and 2.5 equivalents of compound d-1-3 was separately prepared LDA (lithium diisopropylamide). Was added dropwise and the resulting mixture was stirred for 75 minutes. Then, the solution which melt | dissolved 15 g of compound d-1-2 in 30 mL of THF was added dropwise, and the obtained mixture was stirred at 0 degreeC for 1 hour, and it stirred at room temperature overnight. After concentration, 150 mL of water was added, the obtained liquid was separated and extracted with 150 mL of methylene chloride, the obtained organic layer was washed with brine, and the organic layer was concentrated. After recrystallizing the obtained crystals with methanol, 18.9 g of compound d-1-4 was obtained.

(iii) Preparation of Compound d-1-5

13.2 g of compound d-1-4 and 1.7 g of PPTS (pyridinium para-toluenesulfonate) were added to 1000 mL of toluene, and the obtained mixture was heated to reflux for 5 hours under a nitrogen atmosphere. After concentration, the obtained liquid was separated into saturated aqueous sodium hydrogen carbonate solution and methylene chloride, and the obtained organic layer was concentrated. The obtained crystals were recrystallized from methanol and methylene chloride to give 11.7 g of a compound d-1-5.

(iv) Preparation of Exemplary Dye D-1-1a

4.0 g of compound d-1-5 and 2.2 g of compound d-1-6 were added to 60 mL of DMF, and the obtained mixture was stirred at 70 ° C. for 4 hours. Thereafter, 2.1 g of the compound d-1-7 was added, and the obtained mixture was heated and stirred at 160 ° C. for 3.5 hours. Then, 19.0 g of ammonium thiocyanate was added, and the obtained mixture was stirred at 130 degreeC for 5 hours. After concentration, 1.3 mL of water was added, the obtained mixture was filtered, and the obtained cake was washed with diethyl ether. The crude purified was dissolved in methanol solution with TBAOH (tetrabutylammonium hydroxide) and purified on Sephadex LH-20 column. Fractions of the main layer were collected, concentrated and 0.2 M nitric acid solution was added, the precipitate was filtered off, washed with water and diethyl ether to obtain 600 mg of compound D-1-1b. The purified product was dissolved in a methanol solution, 1M nitric acid was added, and the precipitate was filtered and washed with water and diethyl ether to obtain 570 mg of compound D-1-1a. After treating compound D-1-1b with TBAOH methanol solution, water was added and the precipitate was filtered to obtain compound D-1-1c as a residue.

The structure of the obtained compound D-1-1a was confirmed by NMR measurement and MS measurement.

When obtained example pigment | dye D-1-1a was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, trifluoroacetic acid 0.1v / v%) solvent, and the spectral absorption measurement was carried out , The maximum absorption wavelength was 568 nm.

(Example Preparation of Pigment D-1-21a)

Compound d-2-4 was prepared according to the method shown in the following scheme, and exemplary pigment D-1-21a was prepared in the same manner as exemplary pigment D-1-1a.

The structure of obtained compound D-1-21a was confirmed by MS measurement.

MS-ESI m / z = 1125.2 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 570 nm.

(Example Preparation of Pigment D-1-16a)

Compound d-3-2 was prepared according to the method shown in the following scheme, and exemplary pigment D-1-16a was prepared in the same manner as exemplary pigment D-1-1a.

The structure of obtained compound D-1-16a was confirmed by MS measurement.

MS-ESI m / z = 1315.4 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 574 nm.

(Example Preparation of Pigment D-1-17a)

Compound d-4-3 was prepared according to the method shown in the following scheme, and exemplary pigment D-1-17a was prepared in the same manner as exemplary pigment D-1-1a.

The structure of obtained compound D-1-17a was confirmed by MS measurement.

MS-ESI m / z = 1367.6 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 572 nm.

(Example Preparation of Pigment D-1-22a)

Compound d-5-6 was prepared according to the method shown in the following scheme, and exemplified dye D-1-22a was prepared in the same manner as exemplified dye D-1-1a.

The structure of obtained compound D-1-22a was confirmed by MS measurement.

MS-ESI m / z = 1017.1 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 570 nm.

(Example Preparation of Pigment D-1-23a)

Compound d-6-3 was prepared according to the method shown in the following scheme, and exemplary pigment D-1-23a was prepared in the same manner as exemplary pigment D-1-1a.

The structure of obtained compound D-1-23a was confirmed by MS measurement.

MS-ESI m / z = 1121.2 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 571 nm.

(Example Preparation of Pigment D-1-24a)

Exemplary dye D-1-24a was produced in the same manner as Exemplary Dye D-1-21a except that Compound d-7-1 was used instead of Compound d-2-2.

The structure of obtained compound D-1-24a was confirmed by MS measurement.

MS-ESI m / z = 1041.1 (MH) ⁺

When obtained example pigment | dye D-1-24a was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solvent, and the spectral absorption measurement was carried out , The maximum absorption wavelength was 570 nm.

(Example Preparation of Pigment D-9-1a)

Exemplary dye D-9-1a was produced in the same manner as Exemplary Dye D-1-1a, except that Compound d-8-1 was used instead of Compound d-1-7.

The structure of obtained compound D-9-1a was confirmed by MS measurement.

MS-ESI m / z = 1021.1 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 566 nm.

(Example Preparation of Pigment D-1-8a)

Exemplary dye D-1-8a was produced in the same manner as Exemplary Dye D-1-1a, except that Compound d-9-2 was used instead of Compound d-1-2.

The structure of obtained compound D-1-8a was confirmed by MS measurement.

MS-ESI m / z = 989.2 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 565 nm.

(Example Preparation of Pigment D-2-8)

Trifluoroacetylacetone and cesium carbonate were used instead of ammonium thiocyanate, and after the reaction, the crude product was purified by Sephadex LH-20 column, treated with 0.2 N nitric acid solution, filtered and the residue was Except having suspended in the concentrated aqueous ammonia solution, Exemplary Dye D-2-8 was produced in the same manner as the Exemplified Dye D-1-1a.

The structure of obtained compound D-2-8 was confirmed by MS measurement.

MS-ESI m / z = 914.9 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 562 nm.

(Example Preparation of Pigment D-7-1)

(i) Preparation of Compound d-10-2

5.0 g of compound d-10-1 and 1 equivalent of compound d-1-5 were added to 250 mL of ethylene glycol, and the obtained mixture was heated to reflux for 1 hour under light-shielding conditions under a nitrogen atmosphere. Thereafter, 1 equivalent of compound d-1-7 was added, and the obtained mixture was superheated at 130 ° C. for 2 hours. Thereafter, the obtained organic layer was washed with 250 mL of saturated sodium hyposulfite aqueous solution and filtered. The cake obtained was washed with 100 mL of water and 100 mL of diethyl ether. After drying, 8.2 g of compound d-10-2 was obtained.

(ii) Preparation of Exemplary Pigment D-7-1

4.2 g of compound d-10-2 and 36.4 g of ammonium thiocyanate were added to 270 mL of DMF and 135 mL of water, and the obtained mixture was stirred at 140 ° C. for 3 hours. After concentration, the obtained mixture was cooled to 3 ° C., 10 mL of water was added, the obtained mixture was filtered, and the cake was washed with diethyl ether. The crude purified was dissolved in methanol solution with TBAOH (tetrabutylammonium hydroxide) and purified on Sephadex LH-20 column. Fractions of the main layer were collected, concentrated and 0.2 M nitric acid was added, and the precipitate was filtered off and washed with water and diethyl ether. The obtained precipitate was dissolved in a methanol solution again, 1M nitric acid was added, and the precipitate was filtered and washed with water and diethyl ether to obtain 3.4 g of compound D-7-1.

The structure of the obtained compound D-7-1 was confirmed by MS measurement.

MS-ESI m / z: 1111.2 (MH) ⁺

When the obtained example pigment | dye was manufactured so that the density | concentration of a pigment might be 8.5 micromol / L in THF / water (= 6: 4, 0.1-v / v% of a trifluoroacetic acid) solvent, and the spectral absorption measurement was carried out, the absorption maximum wavelength will be 610 nm.

(Example Preparation of Pigment D-8-1a)

Exemplary dye D-8-1a was prepared in the same manner as exemplary dye D-1-1a according to the method given in the scheme below.

When obtained example pigment | dye D-8-1a was manufactured by THF / water (= 6: 4, trifluoroacetic acid 0.1v / v%) solvent so that the density | concentration of a pigment might be 8.5 micromol / L, and the spectral absorption measurement was carried out. , The maximum absorption wavelength was 580 nm.

The metal complex dye produced by the above-mentioned method contains the thing shown below and that whose counter anion is tetrabutylammonium ion.

Experiment 1

(Fabrication of photoelectric conversion element)

On the glass substrate, a tin oxide film doped with fluorine was formed as a transparent conductive film by sputtering, and this film was scribed with a laser to divide the transparent conductive film into two parts. The anatase type titanium oxide particle (average particle diameter: 50 nm) was sintered on one of these electrically conductive films, and the light receiving electrode was produced. Thereafter, a dispersion liquid containing silica particles and rutile titanium oxide in a ratio of 40:60 (mass ratio) was produced, and the dispersion liquid was applied and sintered on the light receiving electrode described above. This formed the insulating porous body. Next, a carbon electrode was formed as a counter electrode.

Next, the glass substrate in which the insulating porous body was formed was immersed for 48 hours in the ethanol solution (3 * 10 <^-4> mol / L) of each sensitizing dye shown in following Table 1. After sensitizing dye-dyed glass was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, the glass was washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of the semiconductor fine particles was 20 g / m ² . The application amount of the sensitizing dye was suitably selected in the range of 0.1-10 mmol / m <^2> according to the kind of sensitizing dye.

As an electrolyte solution, a methoxypropionitrile solution of iodine dimethylpropylimidazolium (0.5 mol / L) and iodine (0.1 mol / L) was used.

(Measurement of Photoelectric Conversion Efficiency)

Pseudo-free light by passing a light of a 500 W xenon lamp (manufactured by Ushio, Inc.) through an AM1.5G filter (manufactured by Oriel Instruments Corp.) and a sharp cutoff filter (Kenko L-42, trade name) Generated sunlight. The intensity of this light was 89 mW / cm ² . This light was irradiated to the produced photoelectric conversion element, and the electricity generated by this was measured by the current voltage measuring device (Keithley-238 type, brand name). The results of measuring the conversion efficiency of the dye-sensitized solar cell thus obtained are shown in Table 1 below. The result is that the conversion efficiency is 7.5% or more; Conversion efficiency is 7.0% or more and less than 7.5% to o; Conversion efficiency is 6.7% or more and less than 7.0%; △ that conversion efficiency is 6.5% or more and less than 6.7%; The conversion efficiency evaluated as less than 6.5% as x. The conversion efficiency was 6.7% or more as the pass.

[Table 1]

As the comparative metal complex dyes, the following sensitizing dyes A to E were used.

From Table 1, it turned out that the dye-sensitized solar cell manufactured using the metal complex pigment | dye of this invention has conversion efficiency. On the other hand, when the comparative dye was used, the conversion efficiency was low.

Experiment 2

1. Preparation of raw compound solution for ITO membrane

5.58 g of indium chloride (III) tetrahydrate and 0.23 g of tin (II) chloride hydrate were dissolved in 100 mL of ethanol to prepare a raw compound solution for an ITO membrane.

2. Preparation of raw compound solution for FTO membrane

0.701 g of tin chloride (IV) pentahydrate was dissolved in 10 mL of ethanol, and 0.592 g of saturated aqueous ammonium fluoride solution was added thereto. This mixture was completely dissolved in an ultrasonic bath for about 20 minutes to prepare a raw compound solution for FTO membrane.

Then, the surface of the heat resistant glass plate with a thickness of 2 mm was chemically washed, and dried. Then, this glass plate was put into the reactor and it heated with the heater. When the heating temperature of the heater reached 450 ° C, the obtained raw material compound solution for ITO membrane was sprayed for 25 minutes using a distance from the nozzle having a diameter of 0.3 mm to a glass plate at 400 mm at a pressure of 0.06 MPa.

After spraying the solution of the raw material compound for ITO membrane, the glass plate was left for 2 minutes (continuous spraying of ethanol on the surface of the glass substrate during this time to suppress the rise of the substrate surface temperature), and when the heating temperature of the heater reached 530 ° C. The obtained raw material compound solution for FTO membrane was sprayed for 2 minutes and 30 seconds under the same conditions. This obtained the transparent electrode plate in which the ITO film | membrane of thickness 530nm and the FTO film | membrane of thickness 170nm are formed in order on the heat resistant glass plate.

For comparison, a transparent electrode plate having only an ITO film having a thickness of 530 mm formed on a heat resistant glass plate having a thickness of 2 mm and a transparent electrode plate having only an FTO film having a thickness of 180 nm formed in the same manner were produced, respectively.

These three transparent electrode plates were heated at 450 ° C. for 2 hours in a heating furnace.

Next, the dye-sensitized solar cell of the structure shown by FIG. 2 of Unexamined-Japanese-Patent No. 4260494 was manufactured using the said three kinds of transparent electrode plates. The oxide semiconductor porous film 15 is formed by dispersing titanium oxide fine particles having an average particle diameter of about 230 nm in acetonitrile to form a paste, and applying the paste on the transparent electrode 11 to a thickness of 15 μm by a bar coating method. The paste was dried and then fired at 450 ° C. for 1 hour. The pigment | dye shown in following Table 2 was supported by this oxide semiconductor porous film 15.

In addition, as the counter electrode 16, a conductive substrate prepared by laminating an ITO film and an FTO film on a glass plate was used, and an electrolyte solution formed of a non-aqueous solution of iodine / iodide was used for the electrolyte layer 17. The planar dimension of the dye-sensitized solar cell was 25 mm × 25 mm.

(Measurement of Photoelectric Conversion Efficiency)

Similar light without ultraviolet rays is passed through a 500 W xenon lamp (manufactured by Ushio, Inc.) through an AM1.5G filter (manufactured by Oriel Instruments Corp.) and a sharp cutoff filter (Kenko L-42, trade name). Generated. The intensity of this light was 89 mW / cm ² . This light was irradiated to the produced photoelectric conversion element, and the electricity generated by this was measured by the current voltage measuring device (Keithley-238 type, brand name). Table 2 shows the results of measuring the conversion efficiency of the dye-sensitized solar cell thus obtained. The result is that the conversion efficiency is 7.5% or more; Conversion efficiency is 7.0% or more and less than 7.5% to o; Conversion efficiency is 6.7% or more and less than 7.0%; △ that conversion efficiency is 6.5% or more and less than 6.7%; The conversion efficiency evaluated as less than 6.5% as x. The conversion efficiency was 6.7% or more as the pass.

[Table 2]

From Table 2, in the case where the conductive layer is made of only the ITO film or only the FTO film, the conversion efficiency is lowered even in the dye-sensitized solar cell of the present invention, and when the FTO film is formed on the ITO film as the conductive layer, It can be seen that the tendency to increase. The trend was also similar in the case of the dye-sensitized solar cell according to the comparative example. In particular, the dye-sensitized solar cell having the FTO film formed on the ITO film as the conductive layer exhibited a conversion efficiency of 7.5% or more and high conversion efficiency. On the other hand, the conversion efficiency of the dye-sensitized solar cell according to the comparative example showed a low value compared to the case of the present invention.

Experiment 3

According to the following method, the test cells (i) and (iv) of the dye-sensitized solar cells of different structures were manufactured, and the photoelectric conversion characteristics were measured and conversion efficiency was calculated | required about these test cells.

(Test cell (i))

The groove | channel of 5 micrometers in depth was formed in the form of a grating circuit pattern by the etching method on the surface of the FTO film | membrane-attached glass plate of size 100mmx100mm. After pattern formation by photolithography, etching was performed using hydrofluoric acid. In order to enable plating formation, the metal conductive layer (seed layer) was formed by the sputtering method, and the metal wiring layer 3 was further formed by additive plating on it. The metal wiring layer 3 was formed from the surface of the transparent substrate 2 to 3 micrometers height in the form of a convex lens. The circuit width was 60 micrometers. An FTO film was formed on the metal wiring layer 3 as the shielding layer 5 by the SPD method at a thickness of 400 nm, and the final granules were used as the electrode substrate i. The cross-sectional shape of the electrode substrate (i) was as shown in FIG. 2 of JP-A-2004-146425.

The titanium oxide dispersion liquid with an average particle diameter of 25 nm was apply | coated on the electrode substrate (i), and the electrode substrate was heated and sintered at 450 degreeC for 1 hour. The electrode substrate was immersed in the ethanol solution of the dye of the present invention for 40 minutes to carry the dye. The electrode substrate was disposed to face the platinum sputtered FTO substrate via a 50 μm-thick thermoplastic polyolefin resin sheet, and the resin sheet portion was thermally melted to fix the two electrode substrates. The electrolyte injection hole is opened on the electrode side which was previously sputtered with platinum, through which a methoxyacetonitrile solution containing 0.5 M of iodine salt and 0.05 M of iodine as a main component was injected, and the methoxyacetonitrile solution was placed between the electrodes. Charged in. Further, the peripheral portion and the electrolyte injection hole were sufficiently sealed with an epoxy-based sealing resin, and silver paste was applied to the current collecting terminal portion. This produced the test cell (i). The photoelectric conversion characteristics of the test cell (i) were evaluated using pseudo sunlight of AM1.5. The results are shown in Table 3.

(Test cell (iv))

The metal wiring layer 3 (gold circuit) was formed by the additive plating method on the FTO film | membrane adhesion | attachment organic substrate of size 100x100 mm. The metal wiring layer 3 (gold circuit) was formed in the grid | lattice form on the board | substrate surface, and the circuit width of the metal wiring layer was 50 micrometers, and the circuit thickness was 5 micrometers. A 300 nm-thick FTO film was formed on the surface by the SPD method as the shielding layer 5, whereby the final granulated product was used as the test cell (iv). The cross section of the electrode substrate (iv) was tested using SEM-EDX, and there was a misalignment thought to be caused by the bottom portion of the plating resist at the wiring bottom, and no FTO coating was formed in the shadow portion.

The test cell (iv) was manufactured using the electrode substrate (iv). The photovoltaic conversion characteristics of the test cell (iv) were evaluated using pseudo sunlight of AM1.5. The results are shown in Table 3. The result is that the conversion efficiency is 7.5% or more; Conversion efficiency is 7.0% or more and less than 7.5% to o; Conversion efficiency is 6.7% or more and less than 7.0%; To Δ, wherein the conversion efficiency is 6.5% or more and less than 6.7%; The conversion efficiency evaluated as less than 6.5% as x. The conversion efficiency was 6.7% or more as the pass.

[Table 3]

From Table 3, it turns out that the conversion efficiency of the test cell manufactured using the metal complex pigment | dye of this invention shows a high conversion efficiency of 7.5% or more. On the other hand, when the comparative dye was used, the conversion efficiency was at least 6.5% and less than 6.7%.

Experiment 4

Sample cells (A) to (D) of the dye-sensitized solar cell were manufactured, the photoelectric conversion characteristics of each cell were evaluated, and conversion efficiency was obtained.

(Production of Sample Cell (A))

1. Fabrication of Semiconductor Films

5 g of titanium hydride was suspended in 1 liter of pure water, and 400 g of 5 mass% hydrogen peroxide solution was added over 30 minutes. Next, the mixture was heated and dissolved at 80 ° C. to prepare a solution of peroxotitanic acid. 90 volume% was aliquoted from the total amount of this solution, and it adjusted to pH 9 by adding concentrated ammonia water. The product was placed in an autoclave and subjected to hydrothermal treatment at 250 ° C. under saturated vapor pressure for 5 hours. This produced the titania colloidal particle (A). The titania colloidal particles thus obtained consisted of anatase type titanium oxide having high crystallinity as measured by X-ray diffraction.

Next, the titania colloid particle (A) obtained above was concentrated to 10 mass%, and it mixed with the peroxotitanic acid solution. Hydroxypropyl cellulose was added to the mixture as a film forming aid so that the amount of titanium in the mixed solution was converted into TiO _{2 so} that the amount of hydroxypropyl cellulose became 30 mass% with respect to the mass of TiO ₂ . This produced the coating liquid for semiconductor film formation.

Next, the said coating liquid was apply | coated on the transparent glass substrate in which fluorine-doped tin oxide is formed as an electrode layer, and it naturally dried. Thereafter, the coating liquid was irradiated with ultraviolet light in a quantity of 6000 mJ / cm ² using a low pressure mercury lamp to decompose peroxo acid to cure the coating film. The coating film was heated at 300 ° C. for 30 minutes to decompose and anneal hydroxypropyl cellulose. This formed the metal oxide semiconductor film (A) on the glass substrate.

2. Adsorption of Metal Complex Pigments

Next, an ethanol solution with a concentration of 3 × 10 ⁻⁴ mol / L was prepared for each metal complex dye of Table 3. These metal complex dye solutions were apply | coated on said metal oxide semiconductor film (A) with 100 rpm spinner, and were dried. This coating and drying step was repeated five times.

3. Preparation of Sample Cell (A)

Tetrapropylammonium iodide was dissolved at a concentration of 0.46 mol / L and iodine was dissolved at a concentration of 0.07 mol / L in a solution in which acetonitrile and ethylene carbonate were mixed at a volume ratio of 1: 5 (acetonitrile: (ethylene carbonate)). I was. This produced the electrolyte solution.

The above-mentioned glass substrate was used as one electrode, and as the counter electrode, these electrodes were disposed facing each other using a transparent glass substrate on which fluorine-doped tin oxide was formed as an electrode and on which platinum was supported. The side was sealed with resin, and the prepared electrolyte solution was interposed between the electrodes. Moreover, the sample cell A was produced between the electrodes by connecting with a lead wire.

(Production of Sample Cell (B))

After the peroxoic acid was decomposed by ultraviolet irradiation to cure the membrane, the membrane was subjected to ion irradiation of Ar gas (manufactured by Nissin Electric Co., Ltd .: ion implantation apparatus, 10 hours at 200 eV). The metal oxide semiconductor film (B) was formed in the same manner as in the case of the oxide semiconductor film (A). The metal complex pigment | dye of following Table 4 was adsorbed, and the metal oxide semiconductor film to which the pigment | dye was adsorbed was manufactured. Using this semiconductor film, a sample cell (B) was produced in the same manner as the sample cell (A).

(Production of Test Cell (C))

Diluted with 18.3 g of titanium tetrachloride with pure water to obtain an aqueous solution containing the titanium compound is 1.0% by mass in terms of TiO _2. While stirring this aqueous solution, 15 mass% aqueous ammonia solution was added and the white slurry of pH 9.5 was obtained. This slurry was filtered and washed to obtain a cake of hydrated titanium oxide gel having a concentration of 10.2% by mass in terms of TiO ₂ . After mixing this cake and 400 g of 5 mass% hydrogen peroxide solutions, the mixture was heated and dissolved at 80 degreeC. This produced the peroxotitanic acid solution. 90 volume% was fractionated from this solution whole quantity, and it concentrated to pH 9 by adding concentrated ammonia water. The product was placed in an autoclave and subjected to hydrothermal treatment at 250 ° C. under saturated vapor pressure for 5 hours. This produced the titania colloidal particle (C).

Next, the metal oxide semiconductor film (C) was formed in the same manner as in the case of the metal oxide semiconductor film (A) using the peroxotitanic acid solution and the titania colloidal particles (C) obtained as described above. The metal complex pigment | dye of following Table 4 was adsorbed, and the metal oxide semiconductor film to which the pigment | dye was adsorbed was manufactured. The sample cell (C) was manufactured by the same method as the sample cell (A) using this semiconductor film.

(Production of Test Cell (D))

Diluted with 18.3 g of titanium tetrachloride with pure water to obtain an aqueous solution containing the titanium compound is 1.0% by mass in terms of TiO _2. While stirring this aqueous solution, 15 mass% aqueous ammonia solution was added and the white slurry of pH 9.5 was obtained. This slurry was filtered and washed and then suspended in pure water. Thus, to obtain a slurry having a concentration of 0.6% by mass of hydrated titanium oxide gel as the TiO ₂ terms. Hydrochloric acid was added to this slurry, and it adjusted to pH2. Next, the slurry was placed in an autoclave and subjected to hydrothermal treatment at 180 ° C. under saturated vapor pressure for 5 hours to prepare titania colloidal particles (D).

Next, the titania colloidal particles (D) were concentrated to 10 mass%, and hydroxypropyl cellulose was added to these particles as a film forming aid so that the amount of hydroxypropyl cellulose became 30 mass% in terms of TiO ₂ . This produced the coating liquid for semiconductor film formation. Next, the said coating liquid was apply | coated and naturally dried on the transparent glass substrate in which fluorine-doped tin oxide was formed as an electrode layer. Next, the coating liquid was irradiated with ultraviolet light in a quantity of 6000 mJ / cm ² using a low pressure mercury lamp to cure the film. The membrane was also heated at 300 ° C. for 30 minutes to effect decomposition and annealing of hydroxypropyl cellulose. This formed the metal oxide semiconductor film (D). The metal complex pigment | dye of following Table 4 was adsorbed, and the metal oxide semiconductor film to which the pigment | dye was adsorbed was manufactured. The sample cell (D) was manufactured by the same method as the sample cell (A) using the said semiconductor film.

(Measurement of photoelectric conversion characteristics)

Each of the test cells (A) to (D) was irradiated with a light of intensity of 100 W / cm ² using a solar simulator, and Voc (voltage of an open circuit) and Joc (short circuit). Density of generated current), FF (curve factor) and η (conversion efficiency) were measured. Table 4 shows the results of the conversion efficiency.

The result is that the conversion efficiency is 7.5% or more; Conversion efficiency is 7.0% or more and less than 7.5% to o; Conversion efficiency is 6.5% or more and less than 7.0% to Δ; The conversion efficiency evaluated as less than 6.5% as x. The conversion efficiency was 7.0% or more as the pass.

[Table 4]

From Table 4, it can be seen that the dye-sensitized solar cell produced using the metal complex dye of the present invention had a conversion efficiency. On the other hand, when the comparative dye was used, the conversion efficiency was low.

Experiment 5

The photoelectric conversion element was manufactured using the semiconductor fine particle obtained by changing the manufacturing method of a titanium oxide, the photoelectric conversion characteristic was evaluated, and conversion efficiency was calculated | required.

(1) Preparation of titanium oxide by heat treatment method

Titanium Oxide 1A (Brukit Type), Titanium Oxide 1B (Anatase Type) and Titanium Oxide 2B (Rutyl Type)

Using commercially available anatase type titanium oxide 1B (manufactured by Ishihara Sangyo Kaisha, Ltd., trade name: ST-01), the product was heated to about 900 ° C to be converted to brookite-type titanium oxide 1A, and further to about 1,200 ° C. It heated to and converted into rutile type titanium oxide 2B.

(2) Synthesis of Titanium Oxide by Wet Synthesis

Titanium Oxide 2A (Bruchite Type)

954 mL of distilled water was filled in the reaction tank with a reflux condenser, and the distilled water was heated to 95 degreeC. 46 mL of aqueous titanium tetrachloride (Ti content: 16.3 mass%, specific gravity 1.59, purity 99.9%) aqueous solution was added dropwise to the reactor at a rate of about 5.0 mL / min while maintaining the stirring speed at about 200 rpm. At this time, care was taken not to lower the temperature of the reaction solution. As a result, the titanium tetrachloride concentration was 0.25 mol / L (2 mass% in terms of titanium oxide). In the reaction tank, the reaction liquid began to be cloudy immediately after the dropwise addition, but the temperature of the reaction liquid was maintained at that temperature. After completion of the dropwise addition, the temperature was further increased to heat the reaction solution to near the boiling point (104 ° C), and the reaction solution was maintained in this state for 60 minutes to completely terminate the reaction.

After filtering the sol obtained by reaction, the sol was powdered using the 60 degreeC vacuum dryer. This powder was quantitatively analyzed by X-ray diffraction. As a result, the ratio of (peak intensity at the surface of the Brookite type 121) / (peak intensity at the position where three types overlap) was 0.38, and ((main peak intensity of the rutile type) / (peak at the position where three types overlap). Intensity) ratio was 0.05. From the analysis of these data, titanium oxide was crystalline, consisting of about 70.0 mass% of brookite type, about 1.2 mass% of rutile type, and about 28.8 mass% of anatase type. In addition, when the microparticles | fine-particles were observed with the transmission electron microscope, the average particle diameter of the primary particle was 0.015 micrometer.

Titanium Oxide 3A (Bruchite Type)

Titanium trichloride aqueous solution (Ti content: 28 mass%, specific gravity 1.5, purity 99.9%) was diluted with distilled water, and the solution converted into titanium and the concentration was 0.25 mol / L was obtained. At this time, the said solution was ice-cooled so that liquid temperature might not rise, and it kept at 50 degrees C or less. Next, 500 mL of this solution was added to a reaction tank with a reflux condenser, and the solution was heated to 85 ° C while bubbling 80% of ozone gas having a purity of 1% / min from the ozone gas generator at a rate of 1 L / min. To cause an oxidation reaction. The system was kept in this state for 2 hours to completely terminate the reaction. The sol thus obtained was filtered and dried in vacuo to obtain a powder. This powder was quantitatively analyzed by X-ray diffraction. As a result, the ratio of (peak intensity on the surface of the Brookette type 121) / (peak intensity at the position where the three types overlap) was 0.85, and ((main peak intensity of the rutile type) / (peak at the position where the three types overlap). Strength) ratio was zero. From the analysis of these data, titanium dioxide consisted of about 98 mass% of brookite type, 0 mass% of rutile type, 0 mass% of anatase type, and about 2% of amorphous titanium dioxide. In addition, when the microparticles | fine-particles were observed with the transmission electron microscope, the average particle diameter of the primary particle was 0.05 micrometer.

Titanium Oxide 3B (Anatase Type)

145 mL of titanium sulfate solution (Ti: 30 mass%, specific gravity 1.65) was added to 855 mL of distilled water. The titanium sulfate concentration at this time was 1.5 mol / L. The solution was heated to 100 ° C. to hydrolyze to give a white precipitate. This precipitate was filtered and washed, dried and powdered using a vacuum dryer at 60 deg. X-ray diffraction analysis showed that the sample was anatase. In addition, when the microparticles | fine-particles were observed with the transmission electron microscope, the average particle diameter of the primary particle was 0.025 micrometer.

Comparative titanium oxide 4 (rutile type)

The titanium dioxide sulfate solution was thermally decomposed by a conventional method, and 950 g (equivalent to 100 g in terms of TiO ₂ ), filtered and washed, was filled with stirring, 80 g of a 48 vol% NaOH solution, and the resulting mixture was obtained. It heated at 95 degreeC for 4 hours. Next, 2 kg of the slurry obtained by sufficiently washing the treated product was filled with 600 g of 30 mass% hydrochloric acid while stirring, and the obtained mixture was heated at 98 ° C. for 5 hours to prepare a titania sol. This titania sol exhibited a rutile crystal structure in X-ray diffraction. The average particle diameter of the titanium oxide fine particles having the rutile crystal structure obtained in this manner was 0.012 μm.

(Manufacturing and evaluation of dye-sensitized photoelectric conversion element)

Using the titanium oxide manufactured by the above-mentioned part as a semiconductor, the photoelectric conversion element which has the structure shown in FIG. 1 of JP-A-2000-340269 was manufactured as follows. Fluorine-doped tin oxide was applied onto a glass substrate, and this was used as a conductive transparent electrode. A paste containing each type of titanium oxide particles as a raw material was prepared, and the paste was applied on the electrode surface with a thickness of 50 μm by a bar coating method. Next, the said paste was baked at 500 degreeC, and the thin layer of about 20 micrometers in thickness was formed. An ethanol solution having a molar concentration of 3 × 10 ⁻⁴ M of the metal complex dyes shown in Table 5 was prepared, and the glass substrate on which a thin layer of titanium oxide was formed was immersed in this ethanol solution and kept at room temperature for 12 hours. As a result, the complex was adsorbed onto the thin layer of titanium oxide.

Platinum was used as the counter electrode using an acetonitrile solution of tetrapropylammonium iodide and lithium iodide as electrolyte solution. This produced the photoelectric conversion element which has the structure shown in FIG. 1 of JP-A-2000-340269. The photoelectric conversion irradiated the light (cutting an infrared part with a filter) of the high-pressure mercury lamp of electric power 160W to the said element, and measured the conversion efficiency at this time. The results are shown in Table 5. The result is that the conversion efficiency is 7.5% or more; Conversion efficiency is 7.0% or more and less than 7.5% to o; To Δ, wherein the conversion efficiency is 6.5% or more and less than 7.0%; It is represented as x that conversion efficiency is less than 6.5%. The conversion efficiency was 7.0% or more as the pass.

[Table 5]

From Table 5, when the metal complex dye of this invention is used, even if titanium oxide is changed, it turns out that conversion efficiency shows the value of a pass level. However, when the comparative dye was used, all of the conversion efficiency was low.

Experiment 6

Various pastes for forming the semiconductor layer or the light scattering layer of the semiconductor electrode constituting the photoelectrode were manufactured, and a dye-sensitized solar cell was produced using this paste.

[Production of Paste]

First, the paste for forming the semiconductor layer or the light scattering layer of the semiconductor electrode which comprises a photoelectrode was manufactured in the following procedure.

(Paste 1)

Spherical TiO ₂ particles (anatase type, average particle diameter: 25 nm; hereinafter, referred to as spherical TiO ₂ particles 1) were put into a nitric acid solution and stirred. This produced the titania slurry. Next, a cellulose binder was added to the titania slurry as a thickener, and the mixture was kneaded. This produced the paste.

(Paste 2)

Spherical TiO ₂ particles 1 and spherical TiO ₂ particles (anatase type, average particle diameter: 200 nm; hereinafter, referred to as spherical TiO ₂ particles 2) were put into a nitric acid solution and stirred. This produced the titania slurry. Next, a cellulose binder was added to the titania slurry as a thickener, and the mixture was kneaded. As a result, the paste: was prepared (weight of the TiO ₂ particles of 1 mass = 30: 70 of the TiO ₂ particles. 2).

(Paste 3)

Paste 1 the rod-shaped TiO ₂ particles; in combination with (anatase type, diameter:: 100 nm, aspect ratio (aspect ratio) 5 or less, rod-shaped referred to as TiO ₂ particles 1), the rod-shaped TiO ₂ particles 1 A paste having a mass of 10:90 by mass versus paste 1 was prepared.

(Paste 4)

The paste 1 was mixed with TiO ₂ particles of 1 BAR, the mass of the paste mass to one of the rod-shaped TiO ₂ particles 1 to produce a paste of 30: 70.

(Paste 5)

The paste 1 was mixed with TiO ₂ particles of 1 BAR, the mass of the paste mass to one of the rod-shaped TiO ₂ particles 1 to produce a paste of 50: 50.

(Paste 6)

Paste 1 is mixed with plate-shaped mica particles (diameter: 100 nm, aspect ratio: 6, hereinafter referred to as plate-shaped mica particles 1), and the paste having a mass of plate-shaped mica particles 1 to a mass of paste 1 is 20:80. Prepared.

(Paste 7)

Paste 1 is mixed with rod-shaped TiO ₂ particles (anatase type, diameter: 30 nm, aspect ratio: 6.3; or less, referred to as rod-shaped TiO ₂ particles 2) to give mass of paste-like TiO ₂ particles 2 to paste 1 The paste whose mass is 30:70 was produced.

(Past 8)

TiO ₂ particles in the paste is 1 BAR (anatase type, diameter: 50 nm, aspect ratio: 6.1, or less; rod-shaped TiO ₂ referred to as particles 3) and mixed, rod-shaped mass to a paste of TiO ₂ particles 31 The paste whose mass is 30:70 was produced.

(Past 9)

TiO ₂ particles in the paste is 1 BAR (anatase type, diameter: 75 nm, aspect ratio: 5.8; hereinafter referred to as rod-shaped TiO ₂ particles. 4) and a mixture, rod-shaped mass to a paste of TiO ₂ particles 41 The paste whose mass is 30:70 was produced.

(Past 10)

Paste 1 is mixed with rod-shaped TiO ₂ particles (anatase type, diameter: 130 nm, aspect ratio: 5.2; or less, referred to as rod-shaped TiO ₂ particles 5) to give a mass of paste-like TiO ₂ particles 5 to paste 1 The paste whose mass is 30:70 was produced.

(Past 11)

Paste 1 is mixed with rod-shaped TiO ₂ particles (anatase type, diameter: 180 nm, aspect ratio: 5 or less, referred to as rod-shaped TiO ₂ particles 6) to give a mass to paste 1 of rod-shaped TiO ₂ particles 6 The paste whose mass is 30:70 was produced.

(Past 12)

Paste 1 is mixed with rod-shaped TiO ₂ particles (anatase type, diameter: 240 nm, aspect ratio: 5 or less, referred to as rod-shaped TiO ₂ particles 7) to give a mass of paste-like TiO ₂ particles 7 to paste 1 The paste whose mass is 30:70 was produced.

(Past 13)

TiO ₂ particles in the paste is 1 BAR (anatase type, diameter: 110 nm, aspect ratio: 4.1; hereinafter, rod-shaped TiO ₂ referred to as particles 8) as a mixture, rod-shaped mass to a paste of TiO ₂ particles 81 The paste whose mass is 30:70 was produced.

(Paste 14)

Paste 1 is mixed with rod-shaped TiO ₂ particles (Anatase type, diameter: 105 nm, aspect ratio: 3.4; or less, referred to as rod-shaped TiO ₂ particles 9) to give mass of paste-like TiO ₂ particles 9 to paste 1 The paste whose mass is 30:70 was produced.

(Dye-sensitized solar cell 1)

According to the procedure described below, a photoelectrode having the same constitution as that of the photoelectrode 12 shown in FIG. 5 of JP-A-2002-289274 was manufactured, and using this photoelectrode, a dye-sensitized solar cell other than the photoelectrode was used. The dye-sensitized solar cell 1 whose dimension which is the same as that of (20) is 10x10 mm was manufactured.

Fluoride on a glass substrate - SnO ₂ doped conductive film (thickness: 500 nm) was formed by a transparent electrode is formed. After this SnO a _second conductive film, coated by the above-mentioned two pastes for screen printing, followed by drying the paste. Thereafter, the paste was calcined in air at 450 ° C. Furthermore, by repeating the screen printing and baking process using paste 4, a semiconductor electrode having the same configuration as that of the semiconductor electrode 2 shown in FIG. 5 on the SnO ₂ conductive film (area of light receiving surface: 10 mm × 10 mm, layer Thickness: 10 µm, thickness of semiconductor layer: 6 µm, thickness of light scattering layer: 4 µm, and content of rod-shaped TiO ₂ particles 1 contained in the light scattering layer: 30 mass%). This produced the photoelectrode which does not contain the sensitizing dye.

Next, the pigment | dye was made to adsorb | suck on a semiconductor electrode as follows. First, anhydrous ethanol dehydrated with magnesium ethoxide was used as a solvent, and the metal complex dye shown in Table 6 below was dissolved in the anhydrous ethanol such that the concentration was 3 × 10 ⁻⁴ mol / L. This produced the pigment solution. Next, the semiconductor electrode was immersed in this solution, thereby adsorb | sucking the pigment | dye to about 1.5 * 10 <^-7> mol / cm <^2> by the semiconductor electrode. This completed the photoelectrode 10.

Next, a platinum electrode (thickness of Pt thin film: 100 nm) having the same shape and size as the photoelectrode as the counter electrode was prepared, and an iodine-based redox solution containing lithium iodine and lithium iodide as an electrolyte E was prepared. Furthermore, the spacer S (brand name: "Surlyn") by the DuPont Company which produced the shape according to the magnitude | size of a semiconductor electrode was produced. As shown in FIG. 3 of JP-A-2002-289274, the photoelectrode 10 and the counter electrode CE were opposingly arranged through the spacer S, and the above-mentioned electrolyte was filled inside. This completed the dye-sensitized solar cell.

(Dye-sensitized solar cell 2)

Photoelectrode and JP having the same constitution as the photoelectrode 10 shown in FIG. 1 of JP-A-2002-289274 in the same procedure as in the dye-sensitized solar cell 1 except that the semiconductor electrode was manufactured as follows. The dye-sensitized solar cell 2 having the same structure as the dye-sensitized solar cell 20 shown in FIG. 3 of -A-2002-289274 was manufactured.

Here, adsorption of the dye to the semiconductor electrode was carried out in the same manner as in the case of the dye-sensitized solar cell 1. First, anhydrous ethanol dehydrated with magnesium ethoxide was used as a solvent, and the metal complex dye shown in Table 6 below was dissolved in the anhydrous ethanol such that the concentration was 3 × 10 ⁻⁴ mol / L. This produced the pigment solution. Next, the semiconductor electrode was immersed in this solution, thereby adsorb | sucking the pigment | dye to about 1.5 * 10 <^-7> mol / cm <^2> by the semiconductor electrode. This completed the photoelectrode 10. The pigment | dye adsorption with respect to the semiconductor electrode in the following dye-sensitized solar cells was performed in the same manner.

Paste 2 was used as a paste for forming a semiconductor layer. On the SnO ₂ conductive film, paste 2 was applied by screen printing and then dried. Thereafter, the paste was baked in air at 450 ° C. to form a semiconductor layer.

Paste 3 was used as the innermost layer forming paste of the light scattering layer. In addition, paste 5 was used as a paste for outermost layer formation of a light scattering layer. And the light scattering layer was formed on the semiconductor layer in the same manner as in the case of the dye-sensitized solar cell 1.

A semiconductor electrode having the same configuration as the semiconductor electrode 2 shown in FIG. 1 of JP-A-2002-289274 on the SnO ₂ conductive film (area of light receiving surface: 10 mm × 10 mm, layer thickness: 10 μm, semiconductor Layer thickness: 3 μm, innermost layer thickness: 4 μm, content of rod-shaped TiO ₂ particles 1 contained in the innermost layer: 10 mass%, thickness of the outermost layer: 3 μm, and contained in the innermost layer Content of the obtained rod-shaped TiO ₂ particles 1 was 50% by mass). This produced the photoelectrode which does not contain a sensitizing dye. In the same manner as in the case of the dye-sensitized solar cell 1, the photoelectrode and the counter electrode CE were disposed to face each other via the spacer S, and the electrolyte was filled therein. This completed the dye-sensitized solar cell 2.

(Dye-sensitized solar cell 3)

In the manufacturing process of the semiconductor electrode, the photoelectrode (shown in FIG. 5 in the same procedure as in the dye-sensitized solar cell 1 except that paste 1 was used as the semiconductor layer forming paste and paste 4 was used as the light scattering layer forming paste) The photoelectrode which has a structure similar to 10), and the dye-sensitized solar cell 3 which have the same structure as the dye-sensitized solar cell 20 shown in FIG. 3 of JP-A-2002-289274 were manufactured. The semiconductor electrode had the following configuration: area of the light receiving surface: 10 mm × 10 mm, layer thickness: 10 μm, thickness of the semiconductor layer: 5 μm, thickness of the light scattering layer: 5 μm, and contained in the light scattering layer Of rod-shaped TiO ₂ particles 1: 30 mass%.

(Dye-sensitized solar cell 4)

In the manufacturing process of the semiconductor electrode, the photoelectrode (shown in FIG. 5 in the same procedure as in the dye-sensitized solar cell 1 except that paste 2 was used as the semiconductor layer forming paste and paste 6 was used as the light scattering layer forming paste) The photoelectrode which has a structure similar to 10), and the dye-sensitized solar cell 4 which have the same structure as the dye-sensitized solar cell 20 shown in FIG. 3 of JP-A-2002-289274 were manufactured. The semiconductor electrode had the following configuration: area of the light receiving surface: 10 mm × 10 mm, layer thickness: 10 μm, thickness of the semiconductor layer: 6.5 μm, thickness of the light scattering layer: 3.5 μm, and contained in the light scattering layer Of the obtained plate-shaped mica particles 1: 20 mass%.

(Dye-sensitized solar cell 5)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye-sensitized solar cell were carried out in the same procedure as in the dye-sensitized solar cell 1, except that paste 2 was used as the semiconductor layer forming paste and paste 8 was used as the light scattering layer forming paste. 5 was prepared. The content of the rod-shaped TiO ₂ particles 3 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

(Dye-sensitized solar cell 6)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye-sensitized solar cell were carried out in the same procedure as in the dye-sensitized solar cell 1 except that paste 2 was used as the semiconductor layer forming paste and paste 9 was used as the light scattering layer forming paste. 6 was prepared. The content of the rod-shaped TiO ₂ particles 4 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

(Dye-sensitized solar cell 7)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye-sensitized solar cell were carried out in the same procedure as in the dye-sensitized solar cell 1 except that paste 2 was used as the semiconductor layer forming paste and paste 10 was used as the light scattering layer forming paste. 7 was prepared. The content of the rod-shaped TiO ₂ particles 5 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

(Dye-sensitized solar cell 8)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye-sensitized solar cell were carried out in the same procedure as in the dye-sensitized solar cell 1 except that paste 2 was used as the semiconductor layer forming paste and paste 11 was used as the light scattering layer forming paste. 8 was prepared. The content of the rod-shaped TiO ₂ particles 6 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

(Dye-sensitized solar cell 9)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye-sensitized solar cell were carried out in the same procedure as in the dye-sensitized solar cell 1 except that paste 2 was used as the semiconductor layer forming paste and paste 13 was used as the light scattering layer forming paste. 9 was prepared. The content of the rod-shaped TiO ₂ particles 8 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

(Dye-sensitized solar cell 10)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye-sensitized solar cell were carried out in the same procedure as in the dye-sensitized solar cell 1 except that paste 2 was used as the semiconductor layer forming paste and paste 14 was used as the light scattering layer forming paste. 10 was prepared. The content of the rod-shaped TiO ₂ particles 9 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

(Dye-sensitized solar cell 11)

In the manufacturing process of the semiconductor electrode, except that a semiconductor electrode (the area of the light receiving surface: 10 mm × 10 mm, the layer thickness: 10 μm) having only the semiconductor layer using only the paste 2, was used in the dye-sensitized solar cell 1 Photoelectrode and dye-sensitized solar cell 11 were manufactured by the same procedure as described above.

(Dye-sensitized solar cell 12)

In the manufacturing process of the semiconductor electrode, the photoelectrode and the dye sensitization were carried out in the same procedure as used in the dye-sensitized solar cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 7 was used as the light scattering layer forming paste. Solar cell 12 was manufactured. The content of the rod-shaped TiO ₂ particles 2 contained in the light scattering layer of the semiconductor electrode was 30 mass%.

[Battery characteristics test]

The battery characteristic test was done and conversion efficiency (eta) of the dye-sensitized solar cell was measured. The battery characteristic evaluation test was carried out using a solar simulator (manufactured by Wacom Electric Co., Ltd., type WXS-85-H) with a condition of irradiation of pseudo sunlight from a xenon lamp through an AM1.5 filter at 1000 W / cm ² . It carried out under the measurement conditions. The current-voltage characteristic was measured using the IV tester, and conversion efficiency (eta) [%] was calculated | required. The results are shown in Table 6. The result is that the conversion efficiency is 7.5% or more; Conversion efficiency is 7.0% or more and less than 7.5% to o; To Δ, wherein the conversion efficiency is 6.5% or more and less than 7.0%; It is represented as x that conversion efficiency is less than 6.5%. The conversion efficiency was 7.0% or more as the pass.

TABLE 6

From Table 6, it turns out that the conversion efficiency of the photoelectrochemical cell manufactured using the metal complex dye of this invention is a pass level. On the other hand, when the comparative dye was used, the conversion efficiency was low.

Experiment 7

Metal alkoxide was added to the metal oxide fine particles, and the mixture was slurried. After apply | coating this slurry to a conductive substrate, the slurry was UV ozone irradiation, UV irradiation, and / or drying, and the electrode was manufactured. Then, the photoelectrochemical cell was produced and conversion efficiency was measured.

(Metal oxide fine particles)

Titanium oxide was used as metal oxide fine particles. As the titanium oxide, P25 powder (manufactured by Degussa GmbH, trade name) having an average particle diameter of 25 nm, which was composed of 30% rutile type and 70% anatase type by mass basis, was used.

(Pretreatment of Metal Oxide Fine Particle Powder)

By heat-treating metal oxide fine particles beforehand, organic substance and water were removed from the surface. In the case of the titanium oxide fine particles, the particles were heated in an oven at 450 ° C. for 30 minutes.

(Measurement of Water Content in Metal Oxide Fine Particles)

The amount of water contained in titanium oxide and P25 powder (manufactured by Degussa GmbH, trade name) stored in an environment having a temperature of 26 ° C. and a humidity of 72% was reduced by weight during thermogravimetric measurement and the amount of water desorbed when heated to 300 ° C. Quantitatively measured by Karl Fischer titration.

The amount of water desorbed when titanium oxide and P25 powder (manufactured by Degussa GmbH, trade name) was heated to 300 ° C. was quantitatively measured by Karl Fischer titration, and 0.253 mg of water was contained in 0.1033 g of fine titanium oxide powder. More specifically, the titanium oxide fine powder contained about 2.5% by weight of water. The metal oxide fine particle powder was heat treated for 30 minutes, and then stored and used in a desiccator.

(Production of Metal Alkoxide Paste)

Examples of metal alkoxides that bind metal oxide fine particles include titanium (IV) tetraisopropoxide (TTIP) as a titanium raw material, zirconium (IV) tetra-n-propoxide as a zirconium raw material, and niobium as a niobium raw material. (V) pentaethoxide (both manufactured by Sigma-Aldrich Company) was used.

The molar concentration ratio of the metal oxide fine particles to the metal alkoxide is appropriately adjusted according to the diameter of the metal oxide fine particles so that the amorphous layer resulting from the hydrolysis of the metal alkoxide does not become excessively thick and sufficient bonding of the particles can be achieved. did. All metal alkoxides were used in the form of 0.1 M ethanol solution. When mixing titanium oxide fine particles and titanium (IV) tetraisopropoxide (TTIP), 3.55 g of 0.1 M TTIP solution was mixed with 1 g of titanium oxide fine particles. At this time, the titanium oxide concentration in the paste thus obtained was about 22 mass%, and the paste had a viscosity suitable for application. In this case, the ratio of titanium oxide, TTIP, and ethanol was 1: 0.127: 3.42 on a mass basis, and 1: 0.036: 5.92 on a molar basis.

Similarly, a mixed paste of titanium oxide fine particles and an alkoxide other than TTIP was also prepared so that the particulate concentration was 22% by mass. In the paste using zinc oxide and tin oxide fine particles, the concentration of the fine particles was 16% by mass. In the case of zinc oxide and tin oxide, the metal alkoxide solution was mixed with the ratio of 5.25 g with respect to 1 g of metal oxide fine particles.

The metal oxide fine particles and the metal alkoxide solution were stirred for 2 hours with a magnetic stirrer in a sealed container to obtain a uniform paste. About the coating method of the paste to an electroconductive substrate, the doctor blade method, the screen printing method, the spray coating method, etc. can be used, The suitable paste viscosity was suitably selected by the coating method. In this embodiment, a method (similar to the doctor blade method) of simply applying a paste with a glass rod was used. In this case, the concentration of the metal oxide fine particles which gave an appropriate paste viscosity was in the range of about 5-30 mass%.

The layer thickness of the amorphous metal oxide resulting from the decomposition of the metal alkoxide is in the range of about 0.1 to 0.6 nm in this example and can be adjusted to an appropriate range.

(Coating and Air Drying of Paste on Conductive Substrate)

Polyethylene terephthalate (PET) film substrate with tin-doped indium oxide (ITO) conductive film (20 Ω / cm ² ) or glass substrate with fluorine-doped tin oxide (FTO) conductive film (10 Ω / cm ² ), Two adhesive tapes were adhere | attached in parallel at regular intervals as a spacer, and each paste manufactured according to the said method was apply | coated uniformly to the board | substrate using the glass rod.

After apply | coating a paste and before dye adsorption, the conditions were changed with or without UV ozone treatment, UV irradiation treatment, and / or a drying process, and the porous membrane was manufactured.

(Dry processing)

The film obtained after application to the conductive substrate was air dried for about 2 minutes at room temperature in the air. In this process, the metal alkoxide in the paste was hydrolyzed by moisture in the air to form amorphous titanium oxide, zirconium oxide, and niobium oxide, which were each amorphous from Ti alkoxide, Zr alkoxide, and Nb alkoxide.

Since the amorphous metal oxide thus produced achieves the role of adhering the metal oxide fine particles to other metal oxide fine particles, and the role of adhering the membrane and the conductive substrate, a porous membrane excellent in mechanical strength and adhesion is obtained only by air drying.

(UV ozone treatment)

UV ozone treatment includes Nippon Laser Electronics Lab Co., Ltd. UV ozone cleaner which is NL-UV253 of manufacture was used. The UV light source included three 4.5 W mercury lamps with emission lines at 185 nm and 254 nm, respectively, and the samples were placed horizontally at a distance of about 6.5 cm from the light source. The introduction of oxygen airflow into the chamber produces ozone. In this example, this UV ozone treatment was performed for 2 hours. The fall of the electroconductivity of the ITO membrane and FTO membrane by this UV ozone treatment was not seen.

(UV treatment)

A UV treatment was carried out for 2 hours in the same manner as in the UV ozone treatment, except that the treatment was carried out by replacing the chamber with nitrogen. The fall of the electroconductivity of the ITO film | membrane and FTO film | membrane by this UV process was not seen.

(Color adsorption)

The 0.5 mM ethanol solution was produced for each pigment | dye using each pigment | dye of Table 7 below. In this experiment, the porous membrane prepared by the above process was dried in an oven at 100 ° C. for 1 hour and then immersed in a solution of sensitizing dye. The porous membrane was left to immerse at room temperature for 50 minutes to adsorb the dye onto the titanium oxide surface. The sample after dye adsorption was washed with ethanol and air dried.

(Manufacture of Photoelectrochemical Cells and Evaluation of Battery Characteristics)

After the dye adsorption, the conductive substrate on which the porous membrane was formed was used as the photoelectrode, and the photoelectrode and the ITO / PET membrane or the FTO / glass counter electrode which were modified by sputtering with platinum fine particles were disposed to face each other. This produced the photoelectrochemical cell. The effective area of the photoelectrode was adjusted to about 0.2 cm ² . As the electrolyte solution, 3-methoxypropionitrile containing 0.5 M LiI, 0.05 MI ₂ , and 5 M t-butylpyridine was used, and this solution was introduced into the gap between both electrodes by capillary action.

Evaluation of battery performance was performed by photocurrent working spectrum measurement under irradiation with a constant photon number (10 ¹⁶ cm ^-2 ) and IV measurement under irradiation with AM1.5 pseudo sunlight (100 mW / cm ² ). These measurements include Bunkoukeiki Co., Ltd. Conversion efficiency was evaluated using the CEP-2000 type | mold spectral sensitivity measuring device of manufacture. The result is that conversion efficiency is 5.0% or more as ⊙; Conversion efficiency is 4.5% or more and less than 5.0% to o; A conversion efficiency of 4.0% or more and less than 4.5% to Δ; The conversion efficiency evaluated as less than 4.0% as x. The conversion efficiency was 4.5% or more as the pass.

[Table 7]

In Table 7, the "UV ozone", "UV", and "dry" columns indicate the presence or absence of UV ozone treatment, UV irradiation treatment, and drying treatment after formation of the porous membrane and before sensitizing dye adsorption, respectively. A treated sample is represented by "(circle)" and an untreated sample is represented by "x".

The column of “Pretreatment of TiO ₂ ” in Table 7 indicates the presence or absence of pretreatment of titanium oxide fine particles (heat treatment in an oven at 450 ° C. for 30 minutes). Samples 7-6, 7-14, 7-22, 7-30, and 7-38 represent samples obtained by using a paste having a high TTIP concentration (molar ratio of titanium oxide: TTIP of 1: 0.356). All other samples (samples 7-1 to 7-5, 7-7 to 7-13, 7-23 to 7-29, 7-31 to 7-37, 7-39, and 7-40) were all molar ratio titanium oxide : It is those obtained using the paste whose TTIP is 1: 0.0356.

From Table 7, the photoelectrochemical battery produced using the metal complex dye of the present invention, regardless of the presence or absence of UV ozone treatment, UV irradiation treatment and drying treatment after formation of the porous membrane and before adsorption of the sensitizing dye, the dye. It can be seen that the conversion efficiency of the photoelectrochemical battery is higher and the conversion efficiency of the pass level is obtained than when using only.

On the other hand, when the comparative pigment | dye was used, it turned out that conversion efficiency is low.

Experiment 8

Using acetonitrile as a solvent, an electrolyte solution in which 0.1 mol / L of lithium iodide, 0.05 mol / L of iodine and 0.62 mol / L of dimethylpropyl imidazolium iodide was dissolved was prepared. Benzimidazole-based compounds of Nos. 1 to 8 shown below were separately added to this solution so as to have a concentration of 0.5 mol / L, respectively, and the compounds were dissolved.

The electrolyte solution of the benzimidazole compound of Nos. 1 to 8 was added dropwise to a porous titanium oxide semiconductor thin film (15 μm thick) having a conductive glass plate carrying the metal complex dye of the present invention. The frame-shaped spacer (thickness 25 micrometers) made from polyethylene film was put here, and this spacer was coat | covered with the platinum counter electrode. This manufactured the photoelectric conversion element.

The photoelectric conversion element thus obtained was irradiated with light having an intensity of 100 mW / cm ² using an Xe lamp as a light source. Table 8 shows the open circuit voltage and the photoelectric conversion efficiency thus obtained. The result is that " ⊙ " with an open circuit voltage of 0.75 V or more; "○" with an open circuit voltage of 0.70 V or more and less than 0.75 V; An open circuit voltage of 0.65 V or more and less than 0.70 V as "Δ"; Open circuit voltages of less than 0.65 V are shown as " x &quot;. In addition, the result shows that conversion efficiency is 7.5% or more as "⊙"; Those having a conversion efficiency of not less than 7.0% and less than 7.5% as "o"; Conversion efficiency is 6.5% or more and less than 7.0% by "Δ"; The conversion efficiency of less than 6.5% is shown as " x &quot;. The open circuit voltage was 0.70 V or more and conversion efficiency was 7.0% or more as the pass.

Moreover, Table 8 also shows the result obtained by the photoelectric conversion element using the electrolytic solution which did not add the benzimidazole type compound.

[Table 8]

Table 8 shows that the open circuit voltage and conversion efficiency of the photoelectric conversion element manufactured using the metal complex dye of the present invention were the pass level.

On the other hand, when the comparative dye was used, it was found that the open circuit voltage and the conversion efficiency were low.

Experiment 9

Dye-sensitized solar cells <1> to <4> were manufactured by the following method. In these dye-sensitized solar cells, the metal complex dyes shown in Table 9 below were adsorbed to obtain Sample Nos. 9-1 to 9-20.

(Dye-sensitized solar cell <1>)

According to the procedure shown below, the photoelectrode (however, the semiconductor electrode 2 was made into 2-layer structure) which has the same structure as the photoelectrode 10 shown in FIG. 1 described in JP-A-2004-152613 was manufactured. did. A dye-sensitized solar cell (light-receiving surface F2 of semiconductor electrode 2) having the same constitution as that of the dye-sensitized solar cell 20 shown in FIG. 1 described in JP-A-2004-152613 except for using the photoelectrode. Area: 1 cm ² ). With respect to each layer of the semiconductor electrode 2 having a two-layer structure, the layer disposed on the side close to the transparent electrode 1 is referred to as the "first layer", and the layer disposed on the side close to the porous body layer PS is "made". 2 layers ".

First, P25 powder (manufactured by Degussa GmbH, trade name) having an average particle diameter of 25 nm, titanium oxide particles having different particle diameters from this, and P200 powder (average particle size: 200 nm, manufactured by Degussa GmbH, trade name); Acetic acetone, ion-exchanged water, and surfactant (Tokyo Chemical Industry Co., Ltd.) were added to the powders so that the total content of P25 and P200 was 15% by mass and the mass ratio of P25 and P200 was P25: P200 = 30: 70. (Manufacture: trade name: Triton-X) was added and kneaded. This produced the 2nd slurry for layer formation (henceforth "slurry 1").

Next, except for using only P25 without using P200, the slurry for forming a first layer (content of P1: 15 mass%; hereinafter referred to as "Slurry 2") by the same manufacturing procedure as that used in slurry 1 Was prepared).

On the other hand, a glass substrate (a transparent conductive glass) on the fluorine-doped SnO ₂ conducting film was formed:: (1.1 mm thickness) (thickness: 700 nm) to form a transparent electrode. On this SnO ₂ conductive film, slurry 2 described above was applied with a bar coater, and then slurry 2 was dried. Thereafter, slurry 2 was calcined at 450 ° C. for 30 minutes in air. In this way, the first layer of the semiconductor electrode 2 was formed on the transparent electrode.

Moreover, the application | coating and baking were repeated using the slurry 1 as above-mentioned, and the 2nd layer was formed on the 1st layer. Thus, on the SnO ₂ conductive film, the semiconductor electrode 2 (area of the light receiving surface: 1.0 cm ² , the total thickness of the first layer and the second layer: 10 μm (thickness of the first layer: 3 μm, first) 2 layer thickness: 7 micrometers)), and the photoelectrode 10 containing no sensitizing dye was produced.

Next, the ethanol solution (density of sensitizing dye: 3x10 <^-4> mol / L) of each pigment | dye of Table 9 was manufactured as a pigment | dye. The photoelectrode 10 was immersed in this solution, and the photoelectrode was immersed for 20 hours under a temperature condition of 80 ° C. Thereby, the pigment | dye was made to adsorb | suck inside the semiconductor electrode in the quantity of about 1.0x10 <^-7> mol / cm <^2> .

Next, a counter electrode CE having the same shape and size as that of the photoelectrode was produced. First, an isopropanol solution of chloroplatinic acid hexahydrate was added dropwise onto the transparent conductive glass, dried in air, and calcined at 450 ° C. for 30 minutes. This obtained platinum sintered counter electrode CE. In the counter electrode CE, holes (1 mm in diameter) for the injection of the electrolyte E were previously formed.

Next, zinc iodide, 1,2-dimethyl-3-propylimidazolium, iodide, and 4-tert-butylpyridine are dissolved in methoxy acetonitrile as a solvent, and a liquid electrolyte (concentration of zinc iodide: 10 mmol / L, the concentration of dimethylpropyl imidazolium iodide: 0.6 mol / L, the concentration of iodine: 0.05 mol / L, and the 4-tert-butylpyridine concentration: 1 mol / L) were prepared.

Next, Mitsui-Dupont Polychemical, Ltd., a spacer S (trade name: "Himilan", ethylene / methacrylic acid random copolymer ionomer film) having a shape in accordance with the size of the semiconductor electrode was prepared, and JP- As shown in FIG. 1 described in A-2004-152613, the photoelectrode and the counter electrode were disposed to face each other via a spacer. Each of the electrodes was bonded by thermal welding. This obtained the casing (electrolyte uncharged) of a battery.

Next, after the liquid electrolyte was injected into the case through the holes of the counter electrode, the holes were closed with a member made of the same material as that of the spacer. This member was further heat-welded to the hole of the counter electrode to seal the hole. This completed the dye-sensitized solar cell <1>.

(Dye-sensitized solar cell <2>)

A dye-sensitized solar cell <2> was manufactured under the same procedure and same conditions as in the case of the dye-sensitized solar cell <1>, except that the concentration of zinc iodide in the liquid electrolyte was changed to 50 mmol / L.

(Dye-sensitized solar cell <3>)

The dye is sensitized under the same procedure and under the same conditions as in the case of the dye-sensitized solar cell <1>, except that lithium iodide is added to the liquid electrolyte instead of zinc iodide and the concentration of lithium iodide in the liquid electrolyte is changed to 20 mmol / L. The solar cell was manufactured.

(Dye-sensitized solar cell <4>)

The dye is sensitized under the same procedure and under the same conditions as in the case of the dye-sensitized solar cell <1>, except that lithium iodide is added to the liquid electrolyte instead of zinc iodide and the concentration of lithium iodide in the liquid electrolyte is changed to 100 mmol / L. The solar cell was manufactured.

[Battery Characteristic Evaluation Test]

According to the following procedure, the battery characteristic evaluation test was done and the photoelectric conversion efficiency ((eta) (%)) of the dye-sensitized solar cells of sample numbers 9-1 to 9-20 shown in following Table 9 was measured.

The battery characteristic evaluation test was carried out using a solar simulator (manufactured by Wacom Electric Co., Ltd., trade name: "WXS-85-H type") of pseudo sunlight from a xenon lamp light source through an AM filter (AM1.5). It carried out under the measurement conditions which make irradiation conditions 100mW / cm <^2> (so-called irradiation conditions of "1 Sun").

For each of the dye-sensitized solar cells of Sample Nos. 9-1 to 9-20, current-voltage characteristics were measured at room temperature using an I-V tester, and photoelectric conversion efficiency η [%] was obtained from these characteristics. The result thus obtained is shown in Table 9 (irradiation conditions of 1 Sun). In addition, the value of the reduction rate of the photoelectric conversion efficiency (η (%)) after 300 hours in the dark at 80 ° C. is also shown in Table 9.

TABLE 9

As is clear from the results shown in Table 9, it was found that the dye of the present invention exhibits high conversion efficiency even when zinc iodide is added to the electrolyte. In contrast, the dye-sensitized solar cell produced using the comparative dye was found to have a lower conversion efficiency after 300 hours.

Experiment 10

1. Preparation of Titanium Dioxide Dispersion

In a 200 mL stainless steel container coated with a fluorine resin inside, 15 g of titanium dioxide fine particles (manufactured by Nippon Aerosil Co., Ltd., Degussa P-25), 45 g of water, a dispersant (manufactured by Sigma-Aldrich Company), 1 g of Triron X-100) and 30 g of zirconia beads of 0.5 mm in diameter (manufactured by Nikkato Corp.) were added and the mixture was dispersed for 2 hours at 1500 rpm using a sand grinder mill (manufactured by Aimex, Ltd.). Carried out. The zirconia beads were separated by filtration from the dispersion thus obtained. Thus, the average particle diameter of the titanium dioxide fine particle in the dispersion liquid obtained was 2.5 micrometers. The particle size is Malvern Instruments, Ltd. It measured using the manufacture Mastersizer (brand name).

2. Preparation of Pigment Adsorption Titanium Oxide Fine Particle Layer (Electrode A)

A conductive glass plate (manufactured by Asahi Glass Co., Ltd., TCO Glass-U, surface resistance: about 30 Ω / m ² ) coated with fluorine-doped tin oxide was prepared, and the conductive layer The adhesive tape for spacers was affixed on the both ends (portion of width 3mm from an end) of the side. Next, the dispersion was applied to the conductive layer using a glass rod. After application of the dispersion, the adhesive tape was peeled off and the dispersion was air dried for 1 day at room temperature. Next, this semiconductor-coated glass plate was placed in an electric furnace (muffle FP-32 type, manufactured by Yamato Scientific Co., Ltd.) and fired at 450 ° C. for 30 minutes. After the semiconductor-coated glass plate was taken out and cooled, the glass plate was immersed in an ethanol solution (concentration: 3 × 10 ⁻⁴ mol / L) of the dye shown in Table 10 for 3 hours. The dye-adsorbed semiconductor-coated glass plate was immersed in 4-tert-butylpyridine for 15 minutes, washed with ethanol and dried naturally to obtain a dye-sensitized titanium oxide fine particle layer. The thickness of the dye-sensitized titanium oxide fine particles layer thus obtained was 10 μm, and the coating amount of the titanium oxide fine particles was 20 g / m ² . The adsorption amount of the dye was different within the range of 0.1 to 10 mmol / m ² depending on the kind of the dye.

3. Fabrication of Dye-Sensitized Solar Cell

Three types of dye-sensitized solar cells a to c were produced according to the following method. In these dye-sensitized solar cells, Sample Nos. 10-1 to 10-15 were obtained using the metal complex dye, nitrogen-containing polymer, and electrophile shown in Table 10 below.

(a) Preparation of dye-sensitized solar cell a

As a solvent, the mixture of the volume ratio 90/10 of acetonitrile and 3-methyl- 2-oxazolidinone was used. To this solvent, iodine and an iodine salt of 1-methyl-3-hexylimidazolium as an electrolyte salt were added to prepare a solution containing 0.5 mol / L of electrolyte salt and 0.05 mol / L of iodine. 10 mass parts of nitrogen containing polymer compounds ((alpha)) were added to this solution with respect to 100 mass parts of (solvent + nitrogen containing polymer compound + salt). Furthermore, 0.1 mol of the electrophiles (β) to the reactive nitrogen atoms of the nitrogen-containing polymer compound were mixed to obtain a uniform reaction solution.

On the other hand, the counter electrode formed of the glass plate which vapor-deposited platinum was mounted on the dye-sensitized titanium oxide fine particle layer formed on the conductive glass plate facing the platinum thin film side down, and the conductive glass plate and the platinum vapor deposition glass plate were fixed. The open end of the granules thus obtained was immersed in the electrolyte solution described above, and the reaction solution was permeated into the dye-sensitized titanium oxide fine particle layer by capillary action.

Next, the granulated body was heated at 80 ° C. for 30 minutes to carry out a crosslinking reaction. Thus, as shown in FIG. 2 of JP-A-2000-323190, on the conductive layer 12 of the conductive glass plate 10, the dye-sensitized titanium oxide fine particle layer 20 and the electrolyte layer 30 , And the dye-sensitized solar cell a-1 (Sample No. 10-1) of the present invention, in which the platinum thin film 42 and the counter electrode 40 formed of the glass plate 41 were laminated in this order.

In addition, the dye-sensitized solar cells a-2 to a-5, in which the photoconductor layer 20 and / or the charge transport layer 30 differ, are repeated by repeating the above-described steps except that the dye is changed as shown in Table 10 below. Got it.

(b) dye-sensitized solar cell b

As described above, the electrode A (20 mm x 20 mm) formed of the titanium oxide fine particle layer dye-sensitized with the dye of the present invention was superimposed on the platinum vapor deposition glass plate of the same size through a spacer. Next, using a capillary phenomenon in the gap between the two glass plates, an electrolyte solution (0.05 mol / L of iodine and 0.5 mol / L of lithium iodide using a mixture of acetonitrile and a volume ratio of 90/10 of 3-methyl-2-oxazolidinone as a solvent) Solution) was penetrated to prepare a dye-sensitized solar cell b-1 (Sample No. 10-2). Moreover, dye-sensitized solar cells b-2 to b-5 were obtained by repeating the said process except having changed the pigment | dye as shown in Table 10 below.

(c) Dye-sensitized solar cell c (electrolyte of JP-A-9-27352)

As mentioned above, electrolyte solution was apply | coated on the electrode A (20 mm x 20 mm) formed from the titanium oxide fine particle layer sensitized with the pigment | dye of this invention, and electrode A was impregnated with electrolyte solution. The electrolyte solution is 1 g of hexaethylene glycol methacrylate (manufactured by Nippon Oil & Fats Co., Ltd., Blenmer PE-350), 1 g of ethylene glycol, and 2-hydroxy-2-methyl-1-phenyl as a polymerization initiator. It was obtained by dissolving 500 mg of lithium iodide in a mixed solution containing 20 mg of propane-1-one (manufactured by Ciba-Geigy Japan, Ltd., Darocur 1173) and vacuum degassing for 10 minutes. Next, the porous titanium oxide layer impregnated with the mixed solution was placed under reduced pressure to remove bubbles in the porous titanium oxide layer. After accelerating the penetration of the monomer, the monomer was polymerized by ultraviolet irradiation, so that a uniform gel of the polymer compound was filled inside the micropores of the porous titanium oxide layer. The product thus obtained was exposed to an iodine atmosphere for 30 minutes to diffuse iodine into the polymer compound, and then the platinum deposited glass plate was superimposed. This obtained the dye-sensitized solar cell c-1 (sample number 10-3). In addition, the dye-sensitized solar cells c-2 to c-5 were obtained by repeating the said process except having changed the pigment | dye as shown in Table 10 below.

5. Measurement of photoelectric conversion efficiency

Pseudo sunlight that does not contain ultraviolet rays was obtained by passing a light of a 500 W xenon lamp (manufactured by Ushio, Inc.) through an AM1.5 filter (manufactured by Oriel Instruments Corp.) and a sharp cut filter (KenkoL-42). The light intensity was set to 89 mW / cm ² .

The electroconductive glass plate 10 and the platinum vapor deposition glass plate 40 of the said photoelectrochemical cell were connected to the crocodile clip, respectively, and each crocodile clip was connected to the current-voltage measuring apparatus (Keithley SMU238 type (brand name)). Pseudo-sun light was irradiated to this photoelectrochemical cell from the electroconductive glass plate 10 side, and the electricity produced in this way was measured using the current voltage measuring device. Table 10 shows the initial value of the conversion efficiency (η) of the photoelectrochemical cell thus obtained and the rate of decrease in conversion efficiency after 300 hours storage in the dark. The initial value of conversion efficiency was 7.0% or more as the pass, and the fall rate of conversion efficiency after 300 hours passed as 7.0% or less.

[Table 10]

(Remarks)

(1) The symbol of a pigment is as having described in the detailed description of this invention.

(2) The nitrogen-containing polymer α and the electrophile β each represent the following compounds.

It can be seen from Table 10 that each of the photoelectrochemical cells produced using the dye of the present invention has an excellent endurance of the conversion efficiency after the initial value of the conversion efficiency and a reduction ratio of the conversion efficiency after 300 hours is 7% or less.

Experiment 11

1. Preparation of Titanium Dioxide Dispersion

Titanium dioxide fine particles (manufactured by Nippon Aerosil Co., Ltd., Degussa P-25) 15 g, water 45 g, dispersant (manufactured by Sigma-Aldrich Company, Triron X) -100) 1 g and 30 g of zirconia beads of 0.5 mm in diameter (manufactured by Nikkato Corp.) were added, and the mixture was subjected to dispersion treatment at 1500 rpm for 2 hours using a sand grinder mill (manufactured by Aimex, Ltd.). did. The zirconia beads were separated by filtration from the dispersion thus obtained. Thus, the average particle diameter of the titanium dioxide fine particle in the dispersion liquid obtained was 2.5 micrometers. The particle size is Malvern Instruments, Ltd. It measured using the manufacture Mastersizer (brand name).

2. Preparation of Pigment Adsorption Titanium Oxide Fine Particle Layer (Electrode A)

A conductive glass plate (manufactured by Asahi Glass Co., Ltd., TCO Glass-U, surface resistance: about 30 Ω / m ² ) coated with fluorine-doped tin oxide was prepared, and the conductive layer The adhesive tape for spacers was affixed on the both ends (portion of width 3mm from an end) of the side. Next, the dispersion was applied to the conductive layer using a glass rod. After application of the dispersion, the adhesive tape was peeled off and the dispersion was air dried for 1 day at room temperature. Next, this semiconductor-coated glass plate was placed in an electric furnace (muffle FP-32 type, manufactured by Yamato Scientific Co., Ltd.) and fired at 450 ° C. for 30 minutes. After the semiconductor-coated glass plate was taken out and cooled, the glass plate was dipped in an ethanol solution (concentration: 3 × 10 ⁻⁴ mol / L) of the dye shown in Table 11 for 3 hours. The dye-adsorbed semiconductor-coated glass plate was immersed in 4-tert-butylpyridine for 15 minutes, then washed with ethanol and dried naturally to obtain a dye adsorption titanium oxide fine particle layer (electrode A). The thickness of the dye-sensitized titanium oxide fine particles layer of the electrode A thus obtained was 10 μm, and the coating amount of the titanium oxide fine particles was 20 g / m ² . The adsorption amount of the dye was different within the range of 0.1 to 10 mmol / m ² depending on the kind of the dye.

3. Fabrication of Dye-Sensitized Solar Cell

The dye-sensitized electrode A (20 mm x 20 mm) manufactured as mentioned above was superimposed on the platinum vapor deposition glass plate of the same size. Next, the electrolyte composition was introduced into the gap between the two glass plates by capillary action to introduce the electrolyte into the titanium oxide electrode. As a result, as shown in FIG. 1, the conductive support 1 made of a conductive glass plate (having a conductive layer provided on a glass transparent substrate), the photoconductor 2, the charge carrier 3, and the counter electrode 4 made of platinum And a glass transparent substrate (not shown) were laminated in order, and it sealed with the epoxy type sealing agent, and manufactured the dye-sensitized solar cell. If the viscosity of the electrolyte composition is high and it is difficult to infiltrate the electrolyte composition using a capillary phenomenon, the electrolyte composition is warmed to 50 ° C., the composition is applied to a titanium oxide electrode, and the electrode is placed under reduced pressure, and the electrolyte composition After sufficiently penetrating and air in the electrode was released, the dye-sensitized solar cell was produced in the same manner by overlapping the platinum-deposited glass plate (large electrode).

The dye-sensitized solar cells of Sample Nos. 11-1 to 11-10 were manufactured according to the process mentioned above by changing a pigment | dye. As electrolyte composition used for each dye-sensitized solar cell, the thing containing 98 mass% and 2 mass% of iodine of the following heterocyclic quaternary salt compounds was used.

4. Measurement of photoelectric conversion efficiency

The light of the 500 W xenon lamp (manufactured by Ushio, Inc.) was passed through an AM1.5 filter (manufactured by Oriel Instruments Corp.) and a sharp cut filter (Kenko L-37) to obtain pseudo sunlight without ultraviolet rays. The light intensity was set to 70 mW / cm ² . This pseudo solar light was irradiated to the dye-sensitized solar cell at 50 ° C, and the generated electricity was measured using a current voltage measuring device (Keithley SMU238 type). The reduction rate of the conversion efficiency after storage in the dark at 85 ° C. for 1,000 hours and the reduction rate of the conversion efficiency after 500 hours of continuous light irradiation were also measured. The results are shown in Table 11 below.

TABLE 11

As shown in Table 11, in the dye-sensitized solar cell of the present invention, the initial values of the conversion efficiency all showed high values of 6.5% or more. After storage in the dark and after continuous light irradiation, all of the above batteries had a reduction rate of 12% or less, indicating that the durability was improved as compared with the comparative example.

Experiment 12

According to the method described below, the dye-sensitized solar cell was produced and the battery was evaluated. The results are shown in Table 12 below.

(1) Preparation of Transparent Conductive Support

As a support for photosensitive electrodes, a flexible transparent conductive support obtained by uniformly applying a thin film of conductive tin oxide at a thickness of 200 nm was used on one surface of a 0.4 mm-thick sheet having a fluorine coated surface.

(2) Production of conductive sheet for counter electrode

On one surface of a 0.4 mm thick Kapton (trademark) film made of polyimide, a platinum film having a thickness of 300 nm was uniformly applied by a vacuum sputtering method. The surface resistance was 5 Ω / cm ² .

(3) Preparation of Semiconductor Particulate Dispersion

J. Am., CJ Barbe et al. Ceramic Soc., Vol. 8, p. A dispersion of anatase type titanium dioxide containing titanium dioxide at a concentration of 11 mass% by using titanium tetraisopropoxide as a titanium raw material and setting the temperature of the polymerization reaction in the autoclave to 230 ° C according to the production method described in 3157. Synthesized. The size of the primary particles of the obtained titanium dioxide particles was 10 to 30 nm. The obtained dispersion was applied to an ultracentrifuge to separate particles, and the aggregates were dried. Thereafter, the aggregate was pulverized in agate mortar to obtain semiconductor fine particles a as a white powder. To 100 mL of a mixed solvent formed with a volume ratio of water and acetonitrile 4: 1, the semiconductor fine particles a were added at a concentration of 32 g per 100 mL of the solvent, and the mixture was uniformly dispersed using a rotating / revolving mixing conditioner. Mixed. As a result, the obtained white semiconductor fine particle dispersion turned out to be a high viscosity paste which has a viscosity of 50-150 N * s / m <^2> , and the paste has the liquid characteristic suitable for use for a coating as it is. In Sample No. 12-6, the powder of polyethylene glycol (PEG) having an average molecular weight of 500,000 was blended in an amount of 7.7 g per 100 mL of solvent. Solid content other than semiconductor microparticles | fine-particles was not added to the other semiconductor microparticle dispersion liquid.

(4) Measurement of solid content in semiconductor fine particle dispersion

Each dispersion was applied to an alkali free glass substrate having a thickness of 1.9 mm using an applicator to a thickness of 40 to 70 μm, and the dispersion coating was dried at room temperature for 1 hour. Then, the granulated material was heated in air at 350 degreeC for 0.5 hour, and the weight change before and behind heating was measured. Solid content other than the semiconductor microparticles | fine-particles of the semiconductor fine particle dispersion liquid used for the said sample number 12-6 was 1.0%. All other solid content except the semiconductor fine particles in the sample was 0.3%.

(5) Preparation of Semiconductor Particle Layer

The dispersion prepared in (3) was applied to the transparent conductive support prepared in (1) using an applicator, and the dispersion coated product was dried at room temperature for 1 hour. This formed the uniform coating layer of 40-70 micrometers in thickness. Furthermore, this coating layer was processed under the conditions shown in Table 12 to prepare a porous semiconductor fine particle layer for dye sensitization. The final average thicknesses of the porous semiconductor fine particle layers were all 6-7 μm.

(6) Preparation of Pigment Adsorption Solution

Each pigment | dye of following Table 12 was melt | dissolved in the mixed solvent which made dry acetonitrile: t-butanol: ethanol into a volume ratio 2: 1: 1 so that pigment | dye density | concentration 3 * 10 <^-4> mol / L may be obtained. To this dye solution, 0.025 mol / L of an organic sulfonic acid derivative having a structure of pC ₉ H ₁₉ -C ₆ H ₄ -O- (CH ₂ CH ₂ -O) _3- (CH ₂ ) ₄ -SO ₃ Na was added as an additive. It melt | dissolved so that a density | concentration was obtained, and the solution for pigment | dye adsorption was prepared.

(7) adsorption of pigment

The board | substrate which apply | coated the said porous semiconductor fine particle layer was immersed in said pigment solution for adsorption, and it was left to soak for 3 hours at 40 degreeC under stirring.

Thus, the pigment | dye was made to adsorb | suck to a semiconductor fine particle layer, and the dye-sensitized electrode (photosensitive electrode) used for the photosensitive layer was manufactured.

(8) Preparation of Dye-Sensitized Solar Cell

The porous semiconductor fine particle layer adsorbed by the dye was finished to form a circular photosensitive electrode having a light receiving area of 1.0 cm ² (about 1.1 cm in diameter). Between the electrodes, a frame-shaped spacer (thickness 20 μm) made of a polyethylene film was inserted between the electrodes, and the platinum-evaporated glass substrate serving as the counter electrode was overlapped with the photosensitive electrode. The spacer portion was heated to 120 ° C. to compress the two substrates. In addition, the edge portion of the battery was sealed with an epoxy resin adhesive. Room temperature melting formed of any one of the compositions of imidazolium ions E1 to E4 / iodine = 50: 1 (mass ratio) described later as an electrolyte solution through a small hole for electrolyte solution injection previously formed in the corner portion of the substrate of the counter electrode. The salt was permeated into the spaces between the electrodes using capillary action.

E1 ： 1,2-dimethyl-3-propylimidazolium iodide

E2: 1-butyl-3-methylimidazolium iodide

E3: 1-methyl-3-propylimidazolium iodide

E4: 1,3-di (2- (2- (2-methoxyethoxy) ethoxy) ethyl) imidazolium iodide

The battery assembly step and the electrolyte solution injection step were all performed in the above dew point -60 ° C dry air. After injection of the molten salt, the battery was sucked in vacuum for several hours, and degassing inside the battery containing the photosensitive electrode and the molten salt was performed. Finally, the small holes were sealed with low melting glass. Thereby, the dye-sensitized solar cell in which the electroconductive support body, the porous semiconductor fine particle electrode (photosensitive electrode) which the pigment | dye adsorbed, the electrolyte solution, the counter electrode, and the support body were laminated | stacked in this order was manufactured.

(9) Evaluation of Dye-Sensitized Solar Cell

A xenon lamp (manufactured by Ushio, Inc.) of 500 W power was fitted with a calibration filter (trade name: AM1.5 direct, manufactured by LOT-Oriel AG) for solar simulation, and a porous semiconductor particulate electrode (photosensitive) was applied to the dye-sensitized solar cell. Similar solar light having an incident light intensity of 100 mW / cm ² was irradiated from the electrode) side. The dye-sensitized solar cell was closely fixed on the stage of the thermostat, and the temperature during irradiation was controlled at 50 ° C. Photocurrent-voltage characteristics by using a current voltage measurement device (Source Measure Unit Model 238, manufactured by Keithley Instruments, Inc.) to scan the DC voltage applied to the device at a constant rate of 10 mV / sec, and measure the photocurrent output by the battery. Was measured. The energy conversion efficiency (eta) obtained by this is shown in following Table 12 with the content of the component (semiconductor microparticles | fine-particles and sensitizing dye) of a battery. The reduction rate of conversion efficiency after continuous light irradiation for 24 hours was also measured. The results of these measurements are shown in Table 12 below.

[Table 12]

As shown in Table 12, when the porous semiconductor fine particle layer which adsorb | sucks the pigment | dye of this invention was formed in the electroconductive support body of conductive polymer, the dye-sensitized solar cell which has a practical level of photoelectric conversion efficiency was obtained (sample number 12-). 1-12-12 and 12-20-12-23). In particular, a dispersion having a solid content of 0.3% other than the semiconductor fine particles is applied to the support, heat treatment is carried out at 120 ° C to 150 ° C, and after the ultraviolet light is irradiated to the layer, the dye of the present invention is adsorbed thereon and porous. In the case of producing the semiconductor fine particle layer, the photoelectric conversion efficiency was increased to 5% or more (Sample Nos. 12-1 to 12-5, 12-10 to 12-12, and 12-20 to 12-23).

When a dispersion having a solid content of 1.0% by mass is applied to a support made of a conductive polymer and the layer is heated to prepare a porous semiconductor fine particle layer, and the dye of the present invention is adsorbed thereon, the case of adsorbing a comparative dye and In comparison, it was found that a dye-sensitized solar cell having a high conversion efficiency was obtained (compare Sample No. 12-6 with Sample Nos. 12-16 to 12-19). In the case of the dye-sensitized solar cell using a comparative dye, the rate of decrease in conversion efficiency after continuous light irradiation was increased to 40% or more. On the other hand, in the case of the dye-sensitized solar cell using the dye of the present invention, it was found that the rate of decrease in conversion efficiency after continuous light irradiation was low at 10% or less, and the battery was excellent in durability.

Experiment 13

A glass sphere having a diameter of 25 µm is substantially uniformly dispersed in a resin composition consisting of an Epicoat 828 (trade name, manufactured by Japan Epoxy Resins, Co., Ltd.), a curing agent, and a plastic paste as an epoxy-based sealant of <Experiment 11>. The dye-sensitized solar cell was produced similarly except having used the sealing agent paste, and the photoelectric conversion efficiency was measured.

The conversion efficiency (η) of each dye-sensitized solar cell thus obtained, the reduction rate of conversion efficiency after dark storage at 85 ° C. for 1,000 hours, and the reduction rate of conversion efficiency after 500 hours of continuous light irradiation are shown in Table 13 below.

[Table 13]

As shown in Table 13, all of the dye-sensitized solar cells of the present invention showed a high initial value of the conversion efficiency of 7.0% or more. After dark preservation and after continuous light irradiation, it was found that all the batteries had a reduction rate of 9.0% or less, which was superior in durability to the batteries of the comparative examples.

Experiment 14

A TiO ₂ suspension prepared according to the sol-gel method was used. By screen-printing coated with a porous layer of TiO ₂ on the FTO glass plate, followed by baking at 450 ℃. The TiO ₂ porous layer is attached by a FTO glass substrate immersed in a 10 ^-4 mol / L ethanol solution of the sensitizing dye for the metal complex dye, or a comparison of the present invention, a dye was adsorbed on the TiO ₂ porous layer.

Separately, 100 mg of 2,2 ', 7,7'-tetrakis (diphenylamino) -9,9'-spirobifluorene were dissolved in 5 mL of chloroform. By lightly coating the resulting solution on the surface of the above-described TiO ₂ porous layer attached FTO glass substrate, it was impregnated with this solution to the holes in the layer. Next, one drop of the solution was directly placed on the surface of the above-described FTO glass substrate with the TiO ₂ porous layer, and the substrate was dried at room temperature. Thereafter, the above-described FTO glass substrate with a porous layer of TiO ₂ was mounted on a vapor deposition apparatus, and further subjected to thermal evaporation under a vacuum of about 10 ⁻⁵ mb to 2,2 ′, 7,7′-tetrakis (100 nm thick). Diphenylamino) -9,9'-spirobifluorene layer was placed. In the vapor deposition apparatus, a gold layer having a thickness of 200 nm serving as a counter electrode was further applied to the above-described FTO glass substrate (coated support) with a TiO ₂ porous layer.

The sample thus prepared was mounted in an optical device including a high pressure lamp, an optical filter, a lens and a mounting. The intensity could be changed by using the filter and moving the lens. The contact was attached to the gold layer and the SnO ₂ layer, respectively, and the sample was attached to the current measuring device, irradiating light to the sample. For the measurement, an appropriate optical filter was used to block light with a wavelength of less than 430 nm. In addition, the apparatus was adjusted such that the radiation intensity substantially corresponded to about 1,000 W / m ² .

The contacts were attached to the gold layer and the SnO ₂ layer, respectively, and both contacts were connected to a potentiostat while irradiating light onto the sample. A sample using the sensitizing dye for comparison (Comparative Example: sensitizing dye A) was generated without a external voltage, but a current of about 90 nA was generated, but the sample using the metal complex dye of the present invention (Example: D-1-1b) The current of about 190 nA was generated. If neither sample was irradiated, the current disappeared.

Experiment 15

Also in the tandem type cell manufactured similarly to Example 1 of JP-A-2000-90989, it was confirmed that the conversion efficiency is high in the metal complex dye of this invention compared with the sample using a comparative dye.

Experiment 16

According to the procedure shown below, the dye-sensitized solar cell shown in FIG. 1 of JP-A-2003-217688 was manufactured.

First, 125 mL of titanium isopropoxide was added dropwise to 750 mL of 0.1 M aqueous nitric acid solution (manufactured by Kishida Chemical Co., Ltd.), and the resulting mixture was heated at 80 ° C. for 8 hours to undergo a hydrolysis reaction to give a sol solution. Prepared. The obtained sol liquid was grown in a titanium autoclave at 250 ° C. for 15 hours. Ultrasonic dispersion was performed in the sol solution for 30 minutes to prepare a colloidal solution containing titanium oxide particles having an average primary particle diameter of 20 nm.

The colloidal solution containing the obtained titanium oxide particles was slowly concentrated by an evaporator until it became a 10 mass% titanium oxide solution, and then polyethylene glycol (manufactured by Kishida Chemical Co., Ltd., mass average molecular weight: 200,000) was used. 40% was added by mass ratio with respect to titanium oxide, and the dispersion liquid in which the titanium oxide particle is disperse | distributed was obtained.

The prepared titanium oxide suspension was applied by a doctor blade method to the transparent conductive film 2 side of the glass substrate 1 on which the SnO ₂ film was formed as the transparent conductive film 2, thereby coating a coating film having an area of about 10 mm × 10 mm. Got it. The coating film was pre-dried at 120 ° C. for 30 minutes, and further calcined under an oxygen environment at 500 ° C. for 30 minutes to form a titanium oxide film having a film thickness of about 10 μm, thereby forming the first layer porous photoelectric conversion layer 4. The first layer porous semiconductor layer of was formed.

Next, 4.0 g of commercially available titanium oxide fine particles (manufactured by TAYCA Corporation, product name: TITANIX JA-1, particle diameter of about 180 nm) and 0.4 g of magnesium oxide powder (manufactured by Kishida Chemical Co., Ltd.) were placed in 20 mL of distilled water, The resulting dispersion was adjusted to pH = 1 with hydrochloric acid. Further, zirconia beads were added, and the mixed solution was subjected to dispersion treatment for 8 hours with a paint shaker, and then the beads were removed. Thereafter, polyethylene glycol (manufactured by Kishida Chemical Co., Ltd., mass average molecular weight: 200,000) was added 40% by mass ratio with respect to titanium oxide, and the resulting mixture was stirred to obtain a dispersion in which titanium oxide particles were dispersed. .

The prepared titanium oxide suspension was apply | coated by the doctor blade method on the 1st layer porous semiconductor layer of the glass substrate 1 in which the titanium oxide film of the 1st layer porous semiconductor layer was formed, and the coating film was obtained. The coating film was pre-dried at 80 ° C. for 20 minutes, and further calcined at about 500 ° C. for 60 minutes in an oxygen environment to form a titanium oxide film 1 having a film thickness of about 22 μm, thereby forming a second layer porous photoelectric conversion layer ( The 2nd layer porous semiconductor layer of 5) was comprised. When the haze rate of the porous semiconductor layer was measured, the haze rate was 84%.

A pigment (first pigment) having a maximum sensitivity in the absorption wavelength region of the absorption spectrum on the short wavelength side, by dissolving the dye S-2 when not to booties in ethanol, the concentration of 3 × 10 ^-4 mol / L of the first dye A dye solution for adsorption was prepared.

The maximum absorption wavelength at the longest wave side in the THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution of merocyanine dye S-2 was 412 nm.

The glass substrate 1 provided with the transparent conductive film 2 and the porous semiconductor layer 3 was immersed in the dye solution for adsorption | suction of the 1st pigment | dye heated at about 50 degreeC for 10 minutes, and was made to the porous semiconductor layer 3 The first pigment was adsorbed. Thereafter, the glass substrate 1 was washed several times with anhydrous ethanol and dried at about 60 ° C. for about 20 minutes. Thereafter, the glass substrate 1 was dipped in 0.5 N hydrochloric acid for about 10 minutes, and then washed with ethanol to desorb the first dye adsorbed onto the second layer porous semiconductor layer. In addition, the glass substrate 1 was dried at about 60 degreeC for about 20 minutes.

Next, as a pigment | dye (second pigment | dye) which has a maximum sensitivity absorption wavelength range in a long wavelength side in an absorption spectrum, a comparative pigment | dye or the metal complex dye of this invention is melt | dissolved in ethanol, and concentration 3 * 10 <^-4> mol / L A dye solution for adsorption of the second dye was prepared.

Here, the maximum absorption wavelength of the longest wave side in the THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution of the used dye is 568 nm in the case of the metal complex dye D-1-1a of the present invention. And comparative dye A was 552 nm.

The glass substrate 1 provided with the transparent conductive film 2 and the porous semiconductor layer 3 was immersed in the dye solution for adsorption of a 2nd pigment | dye for 15 minutes under normal pressure at room temperature, and it made it into the porous semiconductor layer 3 2 pigments were adsorbed. Thereafter, the glass substrate 1 was washed several times with anhydrous ethanol and dried at about 60 ° C. for about 20 minutes. When the haze rate of the porous semiconductor layer was measured, the haze rate was 84% (when using a comparative dye) and 85% (when using the metal complex dye of the present invention).

Next, dimethylpropyl imidazolium iodide is dissolved in a 3-methoxypropionitrile solvent so that the concentration is 0.5 mol / L, lithium iodide is 0.1 mol / L, and iodine is 0.05 mol / L, and oxidized. A reducing electrolyte was prepared. The counter electrode side which consists of the porous semiconductor layer 3 side of the glass substrate 1 provided with the porous semiconductor layer 3 which adsorb | sucked the 1st pigment | dye and the 2nd pigment | dye, and the ITO glass plate which has platinum as a counter electrode layer 8. The platinum side of the support body 20 of the supporter 20 was installed so as to face each other, the prepared redox electrolyte was injected into the space between both sides, and the surroundings were sealed with an epoxy resin sealant 9 to complete the dye-sensitized solar cell. I was.

Oxidation is performed except that the second layer porous semiconductor layer is formed of the same layer as the first porous semiconductor layer, more specifically, the second layer porous semiconductor layer is formed using a titanium oxide suspension forming the first porous semiconductor layer. The titanium oxide film 2 was produced in the same manner as the titanium film 1, and the solar cell was manufactured and evaluated in the same manner using the same. The haze rate of the porous photoelectric conversion layer was 15% (when using a comparative dye), and 16% (when using the metal complex dye of the present invention).

Table 14 shows the results of evaluating the obtained solar cell according to the measurement conditions: AM-1.5 (100 mW / cm ² ). The results show that the conversion efficiency is 3.5% or more; Conversion efficiency is 2.5% or more and less than 3.5% to o; Conversion efficiency is 2.0% or more and less than 2.5% by?; The conversion efficiency evaluated less than 2.0% as x.

[Table 14]

It was found that the metal complex dye of the present invention is excellent in photoelectric conversion efficiency and effective in this system.

Experiment 17

4.0 g of commercially available titanium oxide particles (TAYCA Corporation, average particle diameter 20 nm) and 20 mL of diethylene glycol monomethyl ether were dispersed for 6 hours with a paint shaker using hard glass beads, and then the beads were removed, Titanium oxide suspension was prepared. Next, this titanium oxide suspension was applied to a glass plate (electrode layer) to which a tin oxide conductive layer was previously attached using a doctor blade, preliminarily dried at 100 ° C. for 30 minutes, and then calcined at 500 ° C. in an electric furnace for 40 minutes. The titanium oxide film (semiconductor material) was formed on the glass plate. Separately, the sensitizing dye or the comparative dye of the present invention was dissolved in ethanol to obtain a photosensitizing dye solution.

The density | concentration of this photosensitizer dye solution was 5x10 <^-4> mol / L. Next, the above-mentioned glass plate in which the film-shaped titanium oxide was formed was put in this solution, and the pigment | dye adsorption was performed for 60 minutes at 60 degreeC, and it dried. This formed the photoelectric conversion layer which consists of a semiconductor material and a photosensitizing dye on the glass plate (sample A). The toluene solution (1%) of polyvinylcarbazole (mass average molecular weight 3,000) as a hole transport material was apply | coated on the photoelectric conversion layer of the said sample A, and it dried under reduced pressure, and formed the hole transport layer (sample B). 1.95 g of ethylcarbazole and 2.03 g of 5-nitronaphthoquinone as intermolecular charge transfer complexes were dissolved in 100 mL of acetone, and the resulting solution was repeatedly applied onto the hole transport layer of Sample B to form a conductive layer. Next, a gold electrode (counter electrode) was deposited on the conductive layer to obtain a photoelectric conversion element (sample C). The light of intensity | strength of 100 W / m <^2> was irradiated to the obtained photoelectric conversion element (sample C) by the solar simulator. The results are shown in Table 15. The results show that the conversion efficiency is 1.5% or more; Conversion efficiency is 1.0% or more and less than 1.5% to o; Conversion efficiency is 0.5% or more and less than 1.0% to Δ; The conversion efficiency evaluated less than 0.5% as x.

TABLE 15

It was found that the metal complex dye of the present invention is excellent in photoelectric conversion efficiency and also effective in this system.

&Lt; Example 18 >

(1) formation of the first photoelectric conversion layer

4.0 g of commercially available titanium oxide particles (manufactured by TAYCA Corporation, average particle diameter of 30 nm) and 20 mL of diethylene glycol monomethyl ether were dispersed for 6 hours with a paint shaker using hard glass beads, and then the beads were removed, Titanium oxide suspension was prepared. Next, the titanium oxide suspension was applied to the glass plate to which the tin oxide conductive layer was previously attached using a doctor blade, and the glass plate was preliminarily dried at 100 ° C. for 30 minutes, and then calcined at 500 ° C. in an electric furnace for 40 minutes. A glass plate with a film was obtained.

Separately, the dye [cis-dithiocyanine-N-bis (2,2'-bipyridyl-4,4'-dicarboxylic acid) ruthenium] represented by S-3 below was dissolved in ethanol.

In addition, the maximum absorption wavelength of the longest wave side in the THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution of S-3 was 552 nm.

The density | concentration of this pigment | dye was 3x10 <^-4> mol / L. Next, after putting the said glass plate in which the film-form titanium oxide was formed in this solution, and performing pigment | dye adsorption for 720 minutes at 60 degreeC, it dried and obtained the 1st photoelectric conversion layer (sample A) of this invention.

(2) formation of the second photoelectric conversion layer

4.0 g of commercially available nickel oxide particles (manufactured by Kishida Chemical Co., Ltd., average particle diameter: 100 nm) and 20 mL of diethylene glycol monomethyl ether were dispersed in a paint shaker using glass beads for 8 hours, and then the beads were It was removed to prepare a nickel oxide suspension. Next, this nickel oxide suspension is applied to a glass plate to which a tin oxide conductive layer is attached using a doctor blade, the glass plate is pre-dried at 100 ° C. for 30 minutes, and then calcined at 300 ° C. for 30 minutes, and the glass plate with a nickel oxide film Got.

Separately, the metal complex dye or comparative dye of the present invention was dissolved in dimethyl sulfoxide.

Here, the maximum absorption wavelength of the longest wave side in the THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution of the used dye is 568 nm in the case of the metal complex dye D-1-1a of the present invention. And 568 nm and 552 nm for Comparative D, in the metal complex dye D-1-1b of the present invention.

The density | concentration of the pigment | dye was 1 * 10 <^-4> mol / L. Next, after putting the glass plate which formed the film-form nickel oxide in this solution, and performing pigment | dye adsorption for 60 minutes at 70 degreeC, it dried and obtained the 2nd photoelectric conversion layer (sample B) of this invention.

(3) Place sample B on sample A described above. After putting a liquid electrolyte between these two electrodes, sealing the side surface with resin, the lead wire was attached and the photoelectric conversion element (element structure C) of this invention was manufactured. Here, the liquid electrolyte is dissolved in a mixed solvent of acetonitrile / ethylene carbonate (volume ratio of 1: 4) so that the concentrations of tetrapropylammonium iodide and iodine are 0.46 mol / L and 0.06 mol / L, respectively. Used.

The transparent conductive glass plate equipped with said sample A as one electrode and carrying platinum as a counter electrode was used. After putting a liquid electrolyte between two electrodes, sealing the side surface with resin, the lead wire was attached and the comparative photoelectric conversion element (element structure D) of this invention was manufactured.

The light of intensity | strength of 100 W / m <^2> was irradiated to the obtained photoelectric conversion element (sample C and sample D) by the solar simulator. The results show that the conversion efficiency is 6.5% or more; Conversion efficiency is 6.0% or more and less than 6.5% to o; Conversion efficiency is 5.0% or more and less than 6.0% by?; The conversion efficiency evaluated less than 5.0% as x.

[Table 16]

It was found that the dye of the present invention is excellent in photoelectric conversion efficiency and also effective in this system.

Experiment 19

The example which manufactured the dye-sensitized solar cell manufactured using the polymer electrolyte of JP-A-2001-210390 is demonstrated.

As a coating liquid for producing a titanium oxide film, 4.0 g of commercially available titanium oxide particles (manufactured by TAYCA Corporation, trade name AMT-600, anatase type crystals, average particle diameter of 30 nm, and specific surface area of 50 m ² / g) and diethylene glycol monomethyl Titanium oxide suspension was prepared by dispersing 20 mL of ether with glass beads for 7 hours with a paint shaker and then removing the beads. This titanium oxide suspension was used with a doctor blade to provide a film thickness of about 11 μm and an area of about 10 mm × 10 mm to the transparent conductive film side on the substrate prepared on the glass substrate 1 as SnO ₂ as a transparent conductive film. It was applied and the glass plate was pre-dried at 100 ° C. for 30 minutes and calcined at 460 ° C. for 40 minutes under oxygen. As a result, a titanium oxide film A having a film thickness of about 8 μm was produced.

Next, the metal complex dye or comparative dye of the present invention was dissolved in anhydrous ethanol at a concentration of 3 × 10 ⁻⁴ mol / L to prepare a dye solution for adsorption. The pigment | dye was made to adsorb | suck the pigment | dye by adsorb | sucking this pigment | dye solution for adsorption and the transparent substrate provided with the titanium oxide film | membrane obtained above and a transparent conductive film, respectively, for about 4 hours at 40 degreeC. The substrate was then washed several times with anhydrous ethanol and dried at about 60 ° C. for about 20 minutes.

Next, in the methacrylate monomer unit of the high molecular compound represented by Formula (P), the monomer which consists of a butane tetrayl group which has a central nucleus containing methyl group as R and 8 polyethylene oxide groups and 2 polypropylene oxide groups as A. Used units.

In formula (P), R represents a methyl group, A represents the residue couple | bonded with the ester group via a carbon atom, n represents 2-4.

This monomer unit is dissolved in propylene carbonate (hereinafter referred to as PC) at a concentration of 20% by mass, and azobisisobutyronitrile (AIBN) is used at a concentration of 1% by mass relative to the monomer unit as a polymerization initiator for thermal polymerization. It melt | dissolved in and prepared the monomer solution. The procedure for impregnating the monomer solution into the titanium oxide film is shown below.

A container such as a beaker was installed in the vacuum container, and the titanium oxide film A on the transparent substrate on which the dye having the transparent conductive film was adsorbed was placed in the container, and the vacuum container was vacuumed for about 10 minutes with a rotary pump. The monomer solution was injected into the beaker while maintaining the inside of the vacuum vessel in a vacuum state, and the monomer solution was impregnated for about 15 minutes, so that the monomer solution was sufficiently infiltrated with titanium oxide. The polyethylene separator, PET film, and compression plate were installed and fixed with a jig. Thereafter, the mixture was heated at about 85 ° C. for 30 minutes to thermally polymerize to prepare a high molecular compound.

Next, a redox electrolyte to be impregnated with the high molecular compound was prepared. The redox electrolyte was produced by dissolving lithium iodide in a concentration of 0.5 mol / L and iodine in a concentration of 0.05 mol / L using polycarbonate (PC) as a solvent. In this solution, the polymer compound prepared on the above-described titanium oxide film A was immersed for about 2 hours to infiltrate the redox electrolyte in the polymer compound to prepare a polymer electrolyte.

Then, the electrically conductive substrate provided with the platinum film was provided, the circumference was sealed with the epoxy type sealing agent, and the element A was manufactured.

In addition, after adsorb | sucking a pigment | dye to the titanium oxide film A, although the monomer impregnation process mentioned above was not performed, lithium iodide concentration 0.5 mol / L and iodide concentration 0.05 mol using polycarborate (PC) as a solvent. The redox electrolyte prepared by dissolving to / L was directly injected into the counter electrode to prepare the device B. The light of intensity | strength of 1,000 W / m <^2> was irradiated to the element A and the element B by the solar simulator. The results are shown in Table 17. The results show that the conversion efficiency is 3.5% or more; Conversion efficiency is 2.5% or more and less than 3.5% to o; Conversion efficiency is 2.0% or more and less than 2.5% by?; The conversion efficiency evaluated less than 2.0% as x.

TABLE 17

From Table 17, it turns out that the sample manufactured using the metal complex dye of this invention is excellent in photoelectric conversion efficiency, and the said pigment is also effective also in this system.

Experiment 20

(Fabrication of photoelectric conversion element)

The photoelectric conversion element shown in FIG. 1 was manufactured as follows.

Tin oxide doped with fluorine as a transparent conductive film was formed on the glass substrate by sputtering, this film was scribed with a laser, and the transparent conductive film was divided into two parts.

Next, 32 g of anatase type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) was added to 100 mL of a mixed solvent formed with a volume ratio of water and acetonitrile 4: 1, and the mixture was rotated. It disperse | distributed and mixed uniformly using the mixing conditioner of / combined use type, and the semiconductor fine particle dispersion liquid was obtained. This dispersion liquid was apply | coated to the transparent conductive film, and it heated at 500 degreeC, and manufactured the light receiving electrode.

Thereafter, a dispersion liquid containing silica particles and rutile titanium dioxide at 40:60 (mass ratio) was produced in the same manner, and the dispersion liquid was applied to the above-described light receiving electrode and heated at 500 ° C to form an insulating porous body. . Next, a carbon electrode was formed as a counter electrode.

Next, the glass substrate in which the said insulating porous body was formed was immersed for 5 hours in the ethanol solution of the sensitizing dye (combination of multiple dyes or individual) shown in following Table 18. The glass substrate stained with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of the semiconductor fine particles was 20 g / m ² . As the electrolyte, a methoxypropionitrile solution containing iodine dimethylpropylimidazolium (0.5 mol / L) and iodine (0.1 mol / L) was used.

Here, the maximum absorption wavelength at the longest wave side in the THF / water (= 6: 4, trifluoroacetic acid 0.1 v / v%) solution of the used dye was 581 nm for the sensitizing dye F and 581 for the sensitizing dye G. nm and the sensitizing dye H were 776 nm.

(Measurement of Photoelectric Conversion Efficiency)

The light of a 500 W xenon lamp (manufactured by Ushio, Inc.) is passed through an AM1.5 G filter (manufactured by Oriel Instruments Corp.) and a sharp cut filter (Kenko L-42, trade name) to provide similar sunlight that does not contain ultraviolet light. Generated. The intensity of this light was 89 mW / cm ² . This light was irradiated to the produced photoelectric conversion element, and the electricity generated in this way was measured by the current-voltage measuring device (Keithley-238 type, brand name). Table 18 shows the results of measuring the conversion efficiency of the photoelectrochemical cell thus obtained. The results show that the conversion efficiency is 8.5% or more; ⊙ the conversion efficiency is 7.5% or more and less than 8.5%; ○ that conversion efficiency is 7.3% or more and less than 7.5%; Conversion efficiency is 7.1% or more and less than 7.3% to?; The conversion efficiency evaluated less than 7.1% as x.

[Table 18]

The structures of the sensitizing dyes F to H are shown below.

As shown in Table 18, the electrochemical battery manufactured using the pigment | dye of this invention showed the high conversion efficiency of 7.5% or more, when the metal complex dye of this invention was used in combination with other pigment | dye. On the other hand, according to the comparative example which does not use the metal complex dye of this invention, even when it used in combination with other pigment | dye, conversion efficiency was low as less than 7.3%.

Experiment 21

The manufacturing method of the titanium oxide fine particle layer (electrode A) which adsorb | sucked the pigment | dye of <Experiment 11> was melt | dissolved in ethanol so that a density | concentration may be 1x10 <^-4> mol / L, and the co-adsorbent mentioned above in ethanol was 0.3x10 <^{->. It} was adjusted to the solution dissolved in the range of ⁴ mol to 30x10 ^-4 mol, and adjusted to the solution in which only the pigment was dissolved without using a coadsorbent, and the same except that the electrode was immersed for 3 hours. The dye-sensitized solar cell was produced, and the photoelectric conversion efficiency was measured.

The conversion efficiency (η) of each dye-sensitized solar cell, the reduction rate of conversion efficiency after dark storage at 1,000 ° C. for 1,000 hours, and the reduction rate of conversion efficiency after continuous light irradiation for 500 hours are shown in Table 19 below.

TABLE 19

As is apparent from Table 19, it was confirmed that the sample using the metal complex dye of the present invention was excellent in photoelectric conversion efficiency and durability, and the conversion efficiency and durability were improved by the use of a coadsorbent, and it was also found that it is also effective in this system. .

 Although the present invention has been described with reference to the present embodiments, unless otherwise indicated, the invention is not limited to any of the details of the description, but is intended to be interpreted broadly within the spirit and scope shown in the appended claims. do.

This formal application is directed to 35 USC §199 (Japanese Patent Application No. 2010-127308, filed in Japan on June 2, 2010, and Japanese Patent Application No. 2011-108469, filed in Japan on May 13, 2011). Priority is claimed under a), all of which are hereby incorporated by reference in their entirety.

1 conductive support
2 photosensitive layer
21 pigment (sensitizing dye)
22 Semiconductor Fine Particles
3 charge transfer layer
4 electrodes
5 light receiving electrode
6 external circuit
10 photoelectric conversion element
100 Photoelectrochemical Cells

Claims (20)

Metal complex dye containing ligand LL1 which has a structure represented by following formula (I):

[Wherein,
R ¹ and R ² each independently represent a group represented by any one of the following formulas (II) to (VIII);
L ¹ and L ² each independently represent a group consisting of at least one group selected from the group consisting of an ethenylene group, an ethynylene group and an arylene group, and are conjugated with R ¹ or R ² and bipyridine; The ethenylene group and the arylene group may be substituted or unsubstituted;
R ³ and R ⁴ each independently represent a substituent; n1 and n2 each independently represent an integer of 0 to 3; when n1 is an integer of 1 or more, R ³ may combine with L ¹ to form a ring; when n2 is an integer of 1 or more, R ⁴ may combine with L ² to form a ring; when n1 is an integer of 2 or more, R ³ may be the same as or different from each other, or R ³ may combine with each other to form a ring; when n2 is an integer of 2 or more, R ⁴ may be the same or different from each other, or R ⁴ may combine with each other to form a ring; when n1 and n2 are each an integer of 1 or more, R ³ and R ⁴ may combine with each other to form a ring;
A ¹ and A ² each independently represent an acid group or a salt thereof; n3 and n4 each independently represent an integer of 0 to 3;

(In the meal,
R ⁵ , R ⁸ , R ¹³ , R ¹⁶ and R ¹⁹ each independently represent an alkynyl group or an aryl group which may each have a substituent;
R ⁶ , R ⁹ to R ¹² , R ¹⁴ , R ¹⁵ , R ¹⁷ , R ¹⁸ , R ²⁰ to R ²³ , R ²⁵ , R ²⁶ and R ²⁸ to R ³¹ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, An alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an amino group, a heterocyclic group, or a halogen atom; At least one of R ²⁵ and R ²⁶ represents an alkyl group;
R ⁷ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or a halogen atom;
Any of R ⁶ and R ⁷ , R ⁹ to R ¹² , any of R ¹⁴ and R ¹⁵ , R ¹⁷ and R ¹⁸ , R ²⁰ to R ²³ , any of R ²⁵ and R ²⁶ , and R ²⁸ to R ³¹ May combine with each other to form a ring;
Two R ²⁴ and two R ²⁷ present in the same group may be the same or different from each other, and each represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, but a plurality of R ²⁴ or a plurality of R ²⁷ Do not combine with each other to form a ring;
m1 to m6 each independently represent an integer of 1 to 5;
Y represents S, O, Se, Te or NR ³² ; X represents S, Se, Te or NR ³² ; R ³² represents a hydrogen atom, an alkyl group, an alkenyl group, an alkenyl group, an aryl group, or a heterocyclic group). The metal complex according to claim 1, wherein L ¹ and L ² in Formula (I) each independently represent a substituted or unsubstituted ethenylene group and / or an ethynylene group, and are conjugated with R ¹ or R ² and bipyridine. Pigment. The metal complex dye according to claim 1 or 2, represented by the following formula (IX):
M (LL1) (LL2) ( Z) p · CI formula (IX)
[Wherein M represents a metal atom; LL1 has the same meaning as LL1 in formula (I); LL2 represents a ligand represented by the following formula (X); Z represents a monodentate or bidentate ligand; p represents an integer of 0 to 2;
CI represents the counter ion when counter ions are needed to neutralize the charge in formula (IX);

(In the meal,
R ³³ and R ³⁴ each independently represent a substituent; n5 and n6 each independently represent an integer of 0 to 3; when n5 is an integer of 2 or more, R ³⁴ may be the same as or different from each other, or R ³⁴ may combine with each other to form a ring; when n6 is an integer of 2 or more, R ³³ may be the same as or different from each other, or R ³³ may be bonded to each other to form a ring; when n5 and n6 are each an integer of 1 or more, R ³³ and R ³⁴ may combine with each other to form a ring;
A ³ and A ⁴ each independently represent an acidic group; n7 and n8 each independently represent an integer of 1 to 4). The metal complex dye according to claim 3, wherein the metal element M of the formula (IX) is Ru, Re, Rh, Pt, Fe, Os, Cu, Ir, Pd, W or Co. The metal complex dye according to claim 3, wherein the metal element M of the formula (IX) is Ru. The metal complex dye according to any one of claims 1 to 5, wherein Y in the formulas (II) to (VIII) is S. The metal complex dye according to any one of claims 3 to 6, wherein the ligand LL2 is a ligand represented by the following formula (XI):

[Wherein,
A ⁵ and A ⁶ each independently represent an acid group; R ³⁵ and R ³⁶ each independently represent a substituent; n9 and n10 each independently represent an integer of 0 to 3; when n9 is an integer of 2 or more, R ³⁵ may be the same as or different from each other, or R ³⁵ may be bonded to each other to form a ring; when n10 is an integer of 2 or more, R ³⁶ may be the same as or different from each other, or R ³⁶ may combine with each other to form a ring; when n9 and n10 are each an integer of 1 or more, R ³⁵ and R ³⁶ may combine with each other to form a ring]. The metal complex dye according to any one of claims 3 to 6, wherein the ligand LL2 is a ligand represented by the following formula (XII):

[Wherein, A ⁷ and A ⁸ each independently represent a carboxyl group or a salt thereof]. The metal complex dye according to any one of claims 1 to 8, wherein R ¹ and R ² of the ligand LL1 are each represented by any of formulas (II), (VII) and (VIII). The metal complex dye according to any one of claims 1 to 9, wherein L ¹ and L ² of the ligand LL1 are each an unsubstituted ethenylene group. The metal complex dye according to any one of claims 3 to 10, wherein the metal complex dye represented by the formula (IX) is represented by any one of the following formulas (XIII) to (XV):

[Wherein,
A ⁹ , A ¹⁰ , A ¹¹ , A ¹² , A ¹³ and A ¹⁴ each independently represent a carboxyl group or a salt thereof; R ²⁰⁰ and R ²⁰³ each have the same meaning as R ^{5 in} formula (II); R ²⁰² , R ²⁰⁵ , R ²⁰⁷ , R ²⁰⁸ , R ²¹⁰ , R ²¹¹ , R ²¹³ to R ²¹⁶ and R ²¹⁸ to R ²²¹ each have the same meaning as R ^{6 in} formula (II); At least one of R ²⁰⁷ and R ²⁰⁸ is an alkyl group; At least one of R ²¹⁰ and R ²¹¹ is an alkyl group;
R ²⁰¹ and R ²⁰⁴ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or a halogen atom;
R ²⁰¹ and R ²⁰² , R ²⁰⁴ and R ²⁰⁵ , R ²⁰⁷ and R ²⁰⁸ , R ²¹⁰ and R ²¹¹ , any of R ²¹³ to R ²¹⁶ , and any of R ²¹⁸ to R ²²¹ may combine with each other to form a ring. There is;
R ²⁰⁶ and R ²⁰⁹ each have the same meaning as R ^{24 in} formula (VII); R ²¹² and R ²¹⁷ each have the same meaning as R ^{27 in} formula (VIII);
m7 to m10 each independently represent an integer of 1 to 5;
Z represents a single or bidentate ligand; q1 to q3 each independently represent an integer of 1 to 2]. The metal complex dye according to claim 11, wherein the metal complex dye represented by formula (IX) is represented by formula (XIII) or formula (XV). The metal complex dye according to claim 11, wherein the metal complex dye represented by formula (IX) is represented by formula (XIII). The metal complex dye according to any one of claims 3 to 13, wherein Z is isothiocyanate, isocyanate or isocelenocyanate. The photoelectric conversion element containing the semiconductor fine particle sensitized by the metal complex dye in any one of Claims 1-14. A photoelectric conversion element comprising semiconductor fine particles sensitized by a plurality of dyes, at least one of which is a metal complex dye according to any one of claims 1 to 14. The photoelectric conversion element according to claim 16, wherein at least one of the plurality of dyes has a maximum absorption wavelength at the longest wave side of 600 nm or more in a THF / water (= 6: 4, 0.1 v / v% of trifluoroacetic acid) solution. . Conductive support; And
A semiconductor layer disposed to cover the conductive surface of the conductive support;
The photoelectric conversion element in which the metal complex dye in any one of Claims 1-14, and the coadsorption agent which has one carboxyl group or its salt are supported on the surface of the semiconductor particle of the said semiconductor layer. 19. The photoelectric conversion element according to claim 18, wherein said coadsorbent is represented by the following formula (XVI):

[Wherein Ra represents an alkyl group having only one acidic group or a salt thereof; Rb represents a substituent; n represents an integer of 0 or more; when n is an integer of 2 or more, a plurality of Rb may be the same or different from each other]. A dye-sensitized solar cell comprising the photoelectric conversion element according to any one of claims 15 to 19.

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